Bring CHANGELOG up to date

#67: Issue #66 Updates for Drupal 8.9

Issue #66 Uncomment update_images workflow in prep for merge

Issue #66 Document phpcs.xml.dist feature

Issue #66 Support saving browser output from functional javascript tests

Issue #66 Remove deprecated interface from Behat context class template

Issue #66 Update README

Issue #66 Use an ARG for Drupal version constraint to make is easier to update in future

Issue #66 Be less prescriptive about the Drupal core version

Issue #66 Fix DB host in settings.php dump

Issue #66 Update the database export for Drupal 8.9.16

Issue #66 Include cweagans/composer-patches as a dependency in the container build so it's present and ready to act on modules that include patches

Issue #66 Allow a module to define a phpcs.xml.dist file at the root of the module, and have it used in code sniff checks automatically

Issue #66 Update the branch of drupal_tests_node_example to use for testing

Issue #66 Set xdebug.mode=coverage to satisfy new xdebug requirements for running code coverage