Update release steps and fix changelog heading mistake

Author: alexr00

CHANGELOG.md

@@ -22,7 +22,7 @@
 - There's a new command "Open All Diffs".
 - Comments now show a timestamp using the new VS Code comment `timestamp` API.
 
-## Fixes
+### Fixes
 
 - Markdown content escaped when editing comments. https://github.com/microsoft/vscode-pull-request-github/issues/3254
 - Many spurious user mentions inserted in text. https://github.com/microsoft/vscode-pull-request-github/issues/3257

documentation/releasing.md

@@ -21,7 +21,7 @@
 
 6. Push a tag with the new version number to the appropriate commit (ex. `v0.5.0`).
 
-7. Run the release pipeline, which will cause the extension to be published.
+7. Wait for the release pipeline to finish running.
 
 8. Draft new GitHub release
     - Go to: https://github.com/Microsoft/vscode-pull-request-github/releases