Update CHANGELOG.md: Add missing reflinks (#619)

CHANGELOG.md

@@ -15,6 +15,8 @@ project adheres to [Semantic Versioning](http://semver.org/).
 
 ### Added
 
+[unreleased]: https://github.com/siimon/prom-client/compare/v15.1.0...HEAD
+
 ## [15.1.0] - 2023-12-15
 
 ### Changed
@@ -28,6 +30,8 @@ project adheres to [Semantic Versioning](http://semver.org/).
 - Allow Pushgateway to now require job names for compatibility with Gravel Gateway.
 - Allow `histogram.startTime()` to be used with exemplars.
 
+[15.1.0]: https://github.com/siimon/prom-client/compare/v15.0.0...v15.1.0
+
 ## [15.0.0] - 2023-10-09
 
 ### Breaking
@@ -52,6 +56,8 @@ project adheres to [Semantic Versioning](http://semver.org/).
 
 - Support for OpenMetrics and Exemplars
 
+[15.0.0]: https://github.com/siimon/prom-client/compare/v14.2.0...v15.0.0
+
 ## [14.2.0] - 2023-03-06
 
 ### Changed
@@ -68,12 +74,16 @@ project adheres to [Semantic Versioning](http://semver.org/).
 
 - Add `get` method to type definitions of metric classes
 
+[14.2.0]: https://github.com/siimon/prom-client/compare/v14.1.1...v14.2.0
+
 ## [14.1.1] - 2022-12-31
 
 ### Changed
 
 - Increase compatibility with external build system such as `rollup` by making perf_hooks optional in gc.js
 
+[14.1.1]: https://github.com/siimon/prom-client/compare/v14.1.0...v14.1.1
+
 ## [14.1.0] - 2022-08-23
 
 ### Changed
@@ -102,12 +112,16 @@ project adheres to [Semantic Versioning](http://semver.org/).
 
 - Support gzipped pushgateway requests
 
+[14.1.0]: https://github.com/siimon/prom-client/compare/v14.0.1...v14.1.0
+
 ## [14.0.1] - 2021-11-02
 
 ### Changed
 
 - changed: typedef for pushgateway to reflect js implementation.
 
+[14.0.1]: https://github.com/siimon/prom-client/compare/v14.0.0...v14.0.1
+
 ## [14.0.0] - 2021-09-18
 
 ### Breaking
@@ -145,6 +159,8 @@ project adheres to [Semantic Versioning](http://semver.org/).
 - Add missing type declaration for `client.contentType`. [`3b66641`](https://github.com/siimon/prom-client/commit/3b6664160bdd1555045b03d8f4c421022f30e1db)
 - Modernize some label processing code. [`c9bf1d8`](https://github.com/siimon/prom-client/commit/c9bf1d8e3db3b5fb97faf2df9ca9b9af670288f3)
 
+[14.0.0]: https://github.com/siimon/prom-client/compare/v13.2.0...v14.0.0
+
 ## [13.2.0] - 2021-08-08
 
 ### Changed
@@ -160,6 +176,8 @@ project adheres to [Semantic Versioning](http://semver.org/).
 - feat: added `zero()` to `Histogram` for setting the metrics for a given label combination to zero
 - fix: allow `Gauge.inc/dec(0)` without defaulting to 1
 
+[13.2.0]: https://github.com/siimon/prom-client/compare/v13.1.0...v13.2.0
+
 ## [13.1.0] - 2021-01-24
 
 ### Changed
@@ -173,6 +191,8 @@ project adheres to [Semantic Versioning](http://semver.org/).
 - feat: added the ability to pass labels as an object to `labels()` and `remove()`
 - Added: More examples with commented output
 
+[13.1.0]: https://github.com/siimon/prom-client/compare/v13.0.0...v13.1.0
+
 ## [13.0.0] - 2020-12-16
 
 ### Breaking
@@ -220,6 +240,8 @@ project adheres to [Semantic Versioning](http://semver.org/).
 - feat: added support for adding labels to default metrics (#374)
 - Added CHANGELOG reminder
 
+[13.0.0]: https://github.com/siimon/prom-client/compare/v12.0.0...v13.0.0
+
 ## [12.0.0] - 2020-02-20
 
 ### Breaking
@@ -250,39 +272,51 @@ project adheres to [Semantic Versioning](http://semver.org/).
 - feat: implement GC metrics collection without native(C++) modules.
 - feat: implement advanced event loop monitoring
 
+[12.0.0]: https://github.com/siimon/prom-client/compare/v11.5.3...v12.0.0
+
 ## [11.5.3] - 2019-06-27
 
 ### Changed
 
 - Parameter `compressCount` in Summaries to control compression of data in t-digest.
 - Compress t-digest in Summaries
 
+[11.5.3]: https://github.com/siimon/prom-client/compare/v11.5.2...v11.5.3
+
 ## [11.5.2] - 2019-06-20
 
 ### Changed
 
 - fix: avoid mutation bug in registry
 
+[11.5.2]: https://github.com/siimon/prom-client/compare/v11.5.1...v11.5.2
+
 ## [11.5.1] - 2019-06-13
 
 ### Changed
 
 - fix: guard against missing constructor
 
+[11.5.1]: https://github.com/siimon/prom-client/compare/v11.5.0...v11.5.1
+
 ## [11.5.0] - 2019-06-04
 
 ### Added
 
 - Added `timestamps` toggle to `collectDefaultMetrics` options
 - Export `validateMetricName`
 
+[11.5.0]: https://github.com/siimon/prom-client/compare/v11.4.0...v11.5.0
+
 ## [11.4.0] - 2019-06-04
 
 ### Added
 
 - `nodejs_active_handles` metric to the `collectDefaultMetrics()`. Unlike `nodejs_active_handles_total` it split count of active handles by type.
 - `nodejs_active_requests` metric to the `collectDefaultMetrics()`. Unlike `nodejs_active_requests_total` it split count of active requests by type.
 
+[11.4.0]: https://github.com/siimon/prom-client/compare/v11.3.0...v11.4.0
+
 ## [11.3.0] - 2019-04-02
 
 ### Changed
@@ -294,6 +328,8 @@ project adheres to [Semantic Versioning](http://semver.org/).
 
 - Added a `remove()` method on each metric type, based on [Prometheus "Writing Client Libraries" section on labels](https://prometheus.io/docs/instrumenting/writing_clientlibs/#labels)
 
+[11.3.0]: https://github.com/siimon/prom-client/compare/v11.2.1...v11.3.0
+
 ## [11.2.1]
 
 ### Breaking
@@ -304,6 +340,8 @@ project adheres to [Semantic Versioning](http://semver.org/).
 
 - Updated types for Summary in typescript definition file
 
+[11.2.1]: https://github.com/siimon/prom-client/compare/v11.2.0...v11.2.1
+
 ## [11.2.0]
 
 ### Changed
@@ -315,26 +353,34 @@ project adheres to [Semantic Versioning](http://semver.org/).
 - Added an initial `benchmark` suite which can be run with `npm run benchmarks`.
 - Add support for sliding windows in Summaries
 
+[11.2.0]: https://github.com/siimon/prom-client/compare/v11.1.3...v11.2.0
+
 ## [11.1.3] - 2018-09-22
 
 ### Changed
 
 - Fixed performance by avoiding `Object.assign` on hot paths, as well as
   mutating objects when appropriate.
 
+[11.1.3]: https://github.com/siimon/prom-client/compare/v11.1.2...v11.1.3
+
 ## [11.1.2] - 2018-09-19
 
 ### Changed
 
 - Allow setting Gauge values to NaN, +Inf, and -Inf
 - Fixed `histogram` scrape performance by using `acc.push` instead of `acc.concat`. Fixes #216 with #219
 
+[11.1.2]: https://github.com/siimon/prom-client/compare/v11.1.1...v11.1.2
+
 ## [11.1.1] - 2018-06-29
 
 ### Changed
 
 - Fixed `processOpenFileDescriptors` metric when no custom config was set
 
+[11.1.1]: https://github.com/siimon/prom-client/compare/v11.1.0...v11.1.1
+
 ## [11.1.0] - 2018-06-29
 
 - Added ability to set a name prefix in the default metrics
@@ -346,6 +392,8 @@ project adheres to [Semantic Versioning](http://semver.org/).
   labelset
 - Fixed `AggregatorFactory` losing the aggregator method of metrics
 
+[11.1.0]: https://github.com/siimon/prom-client/compare/v11.0.0...v11.1.0
+
 ## [11.0.0] - 2018-03-10
 
 ### Breaking
@@ -355,6 +403,8 @@ project adheres to [Semantic Versioning](http://semver.org/).
     [best practices](https://prometheus.io/docs/practices/naming/#base-units)
 - Dropped support for node 4
 
+[11.0.0]: https://github.com/siimon/prom-client/compare/v10.2.3...v11.0.0
+
 ## [10.2.3] - 2018-02-28
 
 ### Breaking
@@ -365,6 +415,8 @@ project adheres to [Semantic Versioning](http://semver.org/).
 
 ### Added
 
+[10.2.3]: https://github.com/siimon/prom-client/compare/v10.2.2...v10.2.3
+
 ## [10.2.2] - 2017-11-02
 
 ### Changed
@@ -488,7 +540,6 @@ project adheres to [Semantic Versioning](http://semver.org/).
 - Creating metrics with one argument per parameter - use object literals
   instead.
 
-[unreleased]: https://github.com/siimon/prom-client/compare/v10.2.2...HEAD
 [10.2.2]: https://github.com/siimon/prom-client/compare/v10.2.1...v10.2.2
 [10.2.1]: https://github.com/siimon/prom-client/compare/v10.2.0...v10.2.1
 [10.2.0]: https://github.com/siimon/prom-client/compare/v10.1.1...v10.2.0