Release 2021.4.0: document update

Author: robyww

docs/new-release-procedure.md

@@ -10,7 +10,9 @@
 
 1. **Update Release Notes.**
    In the `rc-yyyy.x` branch, edit the release notes and do the following (firefly/docs/release-notes.md):
-    - Start a new section for this release
+   - Start a new section for this release
+   - Move over any notes from firefly/docs/next-release-details.md
+   - Reset firefly/docs/next-release-details.md (you can see what a reset looks like by looking at the last release)
    - After looking at milestone tags make sure all the important changes are included in the notes.
    - Make sure you edit the docker tags section of this release
    - Update the "Pull Request for this release section", change the text and the URLs for all PR and bug fixes