Update documentation for R202102 release

SETUP/CHANGELOG.md

@@ -3,13 +3,34 @@
 Major changes to this project are documented here. For minor changes,
 see the git history.
 
-## R??????
+## R202102
 Scripts supporting this upgrade are in `SETUP/upgrade/15`
 
 **If you are upgrading from a release before R202009, you must upgrade to
 [R202009](https://github.com/DistributedProofreaders/dproofreaders/releases/tag/R202009)
 first before upgrading to this or later releases.**
 
+**This is the last release to support PHP versions < 7.4 and
+MySQL versions < 5.7.**
+
+* Support MySQL 8.0, PHP 7.2, and PHP 7.4 (chrismiceli, cpeel, bpfoley)
+* New RESTful API - see [API.md](API.md) (cpeel, bpfoley)
+* New user workflow improvements allows P1 to have a quiz requirement (cpeel)
+* Project comments can be either HTML or Markdown (chrismiceli)
+* Format Preview enhancements, including LaTeX math preview (70ray)
+* New dark theme: Charcoal (srjfoo)
+* Special Days projects identified by emojis in round listings (cpeel)
+* PPers can return a project back to the PPVer who returned it to them (70ray)
+* New character suites (bunny-crunch, srjfoo)
+  * `Semitic and Indic transcriptions`
+  * `Symbols collection`
+* Task details and comments are now in Markdown (chrismiceli)
+* Users can be members of up to 6 teams (cpeel)
+* CSS updates and standardization across the codebase (cpeel, srjfoo)
+* Continued work to ensure proper SQL & HTML escaping (chrismiceli, bpfoley)
+* CI/CD & linting improvements (chrismiceli, bpfoley, cpeel)
+* Removed TEI support (cpeel)
+
 
 ## R202009
 Scripts supporting this upgrade are in `SETUP/upgrade/14`

SETUP/INSTALL.md

@@ -16,8 +16,8 @@ The following lists supported versions for the four primary middleware
 components.
 
 ### PHP
-PHP version 7.0 is the minimum supported version. 7.2 has gotten cursory testing
-and seems to work fine. 7.3 and later should work but have not been tested.
+PHP version 7.0 is the minimum supported version. 7.2 and 7.4 also work.
+PHP 8.0 has not been tested.
 
 The following PHP extensions are required. They are listed below with their
 Ubuntu system package names.
@@ -65,23 +65,21 @@ These middleware components match the following major distribution releases:
 * Ubuntu 14.04, Trusty (with PHP 7.0 upgrade)
 * Ubuntu 16.04, Xenial
 * Ubuntu 18.04, Bionic
+* Ubuntu 20.04, Bionic
 * RHEL / CentOS 6.x family (with PHP 7.0 upgrade)
 * RHEL / CentOS 7.x family (with PHP 7.0 upgrade)
+* RHEL / CentOS 8.x family
 
 ## Browser support
 The following are the lowest known supported browser versions for the code:
 * Chrome 50
 * Firefox 50
-* Internet Explorer 11
-  * IE11 does not support `String.prototype.normalize()`, so proofreader inputs
-    are not normalized before being compared against a project's character
-    suites. This could result in a confusing UX if the user added combining
-    characters that would normalize down to a valid character in the project's
-    character suites.
 * Microsoft Edge
 * Opera 40
 * Safari 10
 
+Internet Explorer is not supported.
+
 ## Installing from scratch
 This section assumes that you don't have an existing installation of DP.
 If you're upgrading from a previous version, see [UPGRADE.md](UPGRADE.md).