Add docs for our bc promise and our versioning

[DanielBadura]

closes #622

[DanielBadura]

Should we merge this in one of our 2.x branches?

[github-actions]

Hello 👋

here is the most recent benchmark result:

SubscriptionEngineBench
=======================

+---------------------------+-----------------+-----------------+-----------+-----------------+------------+-------------+
|                           | time (kde mode)                               | memory                                     |
+---------------------------+-----------------+-----------------+-----------+-----------------+------------+-------------+
| subject                   | Tag: <current>  | Tag: base       | time-diff | Tag: <current>  | Tag: base  | memory-diff |
+---------------------------+-----------------+-----------------+-----------+-----------------+------------+-------------+
| benchHandle10000Events () | 3.036s (±0.00%) | 3.044s (±0.00%) | -0.27%    | 34.734mb        | 34.742mb   | -0.02%      |
+---------------------------+-----------------+-----------------+-----------+-----------------+------------+-------------+

SubscriptionEngineBatchBench
============================

+---------------------------+-------------------+-------------------+-----------+-----------------+------------+-------------+
|                           | time (kde mode)                                   | memory                                     |
+---------------------------+-------------------+-------------------+-----------+-----------------+------------+-------------+
| subject                   | Tag: <current>    | Tag: base         | time-diff | Tag: <current>  | Tag: base  | memory-diff |
+---------------------------+-------------------+-------------------+-----------+-----------------+------------+-------------+
| benchHandle10000Events () | 70.461ms (±0.00%) | 68.851ms (±0.00%) | +2.34%    | 34.234mb        | 34.234mb   | 0.00%       |
+---------------------------+-------------------+-------------------+-----------+-----------------+------------+-------------+

SimpleSetupStreamStoreBench
===========================

+----------------------------------------+--------------------+--------------------+-----------+-----------------+------------+-------------+
|                                        | time (kde mode)                                     | memory                                     |
+----------------------------------------+--------------------+--------------------+-----------+-----------------+------------+-------------+
| subject                                | Tag: <current>     | Tag: base          | time-diff | Tag: <current>  | Tag: base  | memory-diff |
+----------------------------------------+--------------------+--------------------+-----------+-----------------+------------+-------------+
| benchLoad1Event ()                     | 913.000μs (±0.00%) | 923.700μs (±0.00%) | -1.16%    | 34.744mb        | 34.744mb   | 0.00%       |
| benchLoad10000Events ()                | 47.171ms (±0.00%)  | 47.808ms (±0.00%)  | -1.33%    | 34.744mb        | 34.744mb   | 0.00%       |
| benchSave1Event ()                     | 969.000μs (±0.00%) | 1.026ms (±0.00%)   | -5.59%    | 34.744mb        | 34.744mb   | 0.00%       |
| benchSave10000Events ()                | 208.552ms (±0.00%) | 217.050ms (±0.00%) | -3.92%    | 34.744mb        | 34.744mb   | 0.00%       |
| benchSave10000Aggregates ()            | 7.565s (±0.00%)    | 7.411s (±0.00%)    | +2.08%    | 34.744mb        | 34.744mb   | 0.00%       |
| benchSave10000AggregatesTransaction () | 4.728s (±0.00%)    | 4.704s (±0.00%)    | +0.50%    | 34.744mb        | 34.744mb   | 0.00%       |
+----------------------------------------+--------------------+--------------------+-----------+-----------------+------------+-------------+

SnapshotsBench
==============

+----------------------------------------+--------------------+-------------------+-----------+-----------------+------------+-------------+
|                                        | time (kde mode)                                    | memory                                     |
+----------------------------------------+--------------------+-------------------+-----------+-----------------+------------+-------------+
| subject                                | Tag: <current>     | Tag: base         | time-diff | Tag: <current>  | Tag: base  | memory-diff |
+----------------------------------------+--------------------+-------------------+-----------+-----------------+------------+-------------+
| benchLoad10000EventsMissingSnapshot () | 50.004ms (±0.00%)  | 47.883ms (±0.00%) | +4.43%    | 33.836mb        | 33.836mb   | 0.00%       |
| benchLoad10000Events ()                | 925.100μs (±0.00%) | 1.019ms (±0.00%)  | -9.21%    | 33.836mb        | 33.836mb   | 0.00%       |
+----------------------------------------+--------------------+-------------------+-----------+-----------------+------------+-------------+

SplitStreamBench
================

+-------------------------+--------------------+--------------------+-----------+-----------------+------------+-------------+
|                         | time (kde mode)                                     | memory                                     |
+-------------------------+--------------------+--------------------+-----------+-----------------+------------+-------------+
| subject                 | Tag: <current>     | Tag: base          | time-diff | Tag: <current>  | Tag: base  | memory-diff |
+-------------------------+--------------------+--------------------+-----------+-----------------+------------+-------------+
| benchLoad10000Events () | 4.365ms (±0.00%)   | 4.434ms (±0.00%)   | -1.54%    | 37.072mb        | 37.072mb   | 0.00%       |
| benchSave10000Events () | 342.407ms (±0.00%) | 348.712ms (±0.00%) | -1.81%    | 37.144mb        | 37.144mb   | 0.00%       |
+-------------------------+--------------------+--------------------+-----------+-----------------+------------+-------------+

PersonalDataBench
=================

+----------------------------------------+--------------------+--------------------+-----------+-----------------+------------+-------------+
|                                        | time (kde mode)                                     | memory                                     |
+----------------------------------------+--------------------+--------------------+-----------+-----------------+------------+-------------+
| subject                                | Tag: <current>     | Tag: base          | time-diff | Tag: <current>  | Tag: base  | memory-diff |
+----------------------------------------+--------------------+--------------------+-----------+-----------------+------------+-------------+
| benchLoad1Event ()                     | 879.100μs (±0.00%) | 881.700μs (±0.00%) | -0.29%    | 34.895mb        | 34.895mb   | 0.00%       |
| benchLoad10000Events ()                | 82.370ms (±0.00%)  | 86.144ms (±0.00%)  | -4.38%    | 34.895mb        | 34.895mb   | 0.00%       |
| benchSave1Event ()                     | 1.540ms (±0.00%)   | 1.492ms (±0.00%)   | +3.17%    | 34.895mb        | 34.895mb   | 0.00%       |
| benchSave10000Events ()                | 245.425ms (±0.00%) | 246.497ms (±0.00%) | -0.43%    | 34.897mb        | 34.897mb   | 0.00%       |
| benchSave10000Aggregates ()            | 11.669s (±0.00%)   | 11.588s (±0.00%)   | +0.70%    | 34.895mb        | 34.895mb   | 0.00%       |
| benchSave10000AggregatesTransaction () | 8.696s (±0.00%)    | 8.756s (±0.00%)    | -0.68%    | 35.396mb        | 35.396mb   | 0.00%       |
+----------------------------------------+--------------------+--------------------+-----------+-----------------+------------+-------------+

SimpleSetupBench
================

+----------------------------------------+--------------------+--------------------+-----------+-----------------+------------+-------------+
|                                        | time (kde mode)                                     | memory                                     |
+----------------------------------------+--------------------+--------------------+-----------+-----------------+------------+-------------+
| subject                                | Tag: <current>     | Tag: base          | time-diff | Tag: <current>  | Tag: base  | memory-diff |
+----------------------------------------+--------------------+--------------------+-----------+-----------------+------------+-------------+
| benchLoad1Event ()                     | 948.300μs (±0.00%) | 932.300μs (±0.00%) | +1.72%    | 33.765mb        | 33.765mb   | 0.00%       |
| benchLoad10000Events ()                | 49.811ms (±0.00%)  | 48.441ms (±0.00%)  | +2.83%    | 33.765mb        | 33.765mb   | 0.00%       |
| benchSave1Event ()                     | 991.400μs (±0.00%) | 996.800μs (±0.00%) | -0.54%    | 33.765mb        | 33.765mb   | 0.00%       |
| benchSave10000Events ()                | 217.273ms (±0.00%) | 216.583ms (±0.00%) | +0.32%    | 33.765mb        | 33.765mb   | 0.00%       |
| benchSave10000Aggregates ()            | 7.547s (±0.00%)    | 7.528s (±0.00%)    | +0.24%    | 33.765mb        | 33.765mb   | 0.00%       |
| benchSave10000AggregatesTransaction () | 4.735s (±0.00%)    | 4.712s (±0.00%)    | +0.47%    | 33.765mb        | 33.765mb   | 0.00%       |
+----------------------------------------+--------------------+--------------------+-----------+-----------------+------------+-------------+

This comment gets update everytime a new commit comes in!