Make changelog headings more consistent

Changelog.md

@@ -1,8 +1,10 @@
-### v2.0.1 (10-Jun-2022)
+# Changelog
+
+## v2.0.1 (10-Jun-2022)
 
 - Fixed an issue where the test summary showed incorrect value under the "Elapsed" column. The value shown previously was a sum of all test durations, which didn't account for parallelization.
 
-### v2.0 (29-May-2022)
+## v2.0 (29-May-2022)
 
 - Test summary now only displays failed tests instead of all executed tests. Displaying all tests made the summary very hard to navigate and caused severe performance issues in repositories with large test suites.
 - Failed tests in test summary now link to the file and the exact code line where the error happened. This link is static and is bound to the commit hash that triggered the workflow.
@@ -12,32 +14,32 @@
 - Added the `annotations.messageFormat` option that can be used to specify the format of the annotation message (the body of the alert box shown in diffs and job overviews).
 - Added `$framework` replacement token that can be used in `annotations.titleFormat` and `annotations.messageFormat` to display the target framework of the associated test.
 
-### v1.4.1 (19-Apr-2022)
+## v1.4.1 (19-Apr-2022)
 
 - Improved test summary formatting and layout.
 
-### v1.4 (18-Apr-2022)
+## v1.4 (18-Apr-2022)
 
 - Added rudimentary support for GitHub Job Summaries (also known as Action Summaries or Step Summaries). Note that this feature is still in private preview and may not be available for your repository. See readme for more information.
 
-### v1.3 (21-Feb-2022)
+## v1.3 (21-Feb-2022)
 
 - Improved formatting of GitHub workflow commands. Newlines are now properly escaped, allowing multiline error messages to be shown inside annotations.
 - Changed default annotation message format from `$name: $outcome` to just `$outcome`. Test name, which was previously included, is now displayed as annotation title instead.
 - Marked package as development dependency.
 
-### v1.2 (22-Feb-2021)
+## v1.2 (22-Feb-2021)
 
 - Added a `format` option that allows customizing message format, with which the test results are reported. Refer to the readme for more information on how to use it.
 
-### v1.1.2 (26-Oct-2020)
+## v1.1.2 (26-Oct-2020)
 
 - Fixed an issue where source information was sometimes not properly extracted from tests implemented as async methods.
 
-### v1.1.1 (01-Oct-2020)
+## v1.1.1 (01-Oct-2020)
 
 - Added a warning message when using this logger outside of GitHub Actions.
 
-### v1.1 (27-Apr-2020)
+## v1.1 (27-Apr-2020)
 
 - Added a switch to disable warnings which are reported if tests were ignored or skipped. Use `--logger "GitHubActions;report-warnings=false"` if you want to do that.