docs: Further improve Release docs (#9925)

* docs: Further improve Release docs

Includes proposal of a new versioning scheme and more accurate representation
of the release candidate process.

* docs: Tidy up headers

bin/build-plugin-zip.sh

@@ -44,19 +44,12 @@ if [ ! -z "$changed" ]; then
 	exit 1
 fi
 
-branch="$(git rev-parse --abbrev-ref HEAD)"
-if [ "$branch" != 'master' ]; then
-	warning "WARNING: You should probably be running this script against the
-         'master' branch (current: '$branch')"
-	sleep 2
-fi
-
 # Do a dry run of the repository reset. Prompting the user for a list of all
 # files that will be removed should prevent them from losing important files!
 status "Resetting the repository to pristine condition. ✨"
 git clean -xdf --dry-run
 warning "🚨 About to delete everything above! Is this okay? 🚨"
-echo -n "[Y]es/[N]o: "
+echo -n "[y]es/[N]o: "
 read answer
 if [ "$answer" != "${answer#[Yy]}" ]; then
 	# Remove ignored files to reset repository to pristine condition. Previous

docs/reference/deprecated.md

@@ -1,4 +1,4 @@
-Gutenberg's deprecation policy is intended to support backwards-compatibility for two minor releases, when possible. The current deprecations are listed below and are grouped by _the version at which they will be removed completely_. If your plugin depends on these behaviors, you must update to the recommended alternative before the noted version.
+Gutenberg's deprecation policy is intended to support backwards-compatibility for releases, when possible. The current deprecations are listed below and are grouped by _the version at which they will be removed completely_. If your plugin depends on these behaviors, you must update to the recommended alternative before the noted version.
 
 # 4.3.0