docs: Setup template for release note process

Add some guidelines for release notes that developers can use to create
release note snippets as features and fixes are implemented.  This will
greatly reduce the work needed at release time.

Signed-off-by: David Brown <david.brown@linaro.org>

Author: d3zd3z

docs/release-notes.d/00readme.md

@@ -0,0 +1,29 @@
+# Pending release notes directory
+
+This directory contains release note entries that have not been merged
+into the main release-notes.md document.
+
+Generally a release note entry should be created for changes that:
+
+- Fix bugs in the code.
+- Implement new features.
+- Change existing behavior.
+
+Release notes are generally not needed for:
+
+- Some documentation improvements.
+- Strictly internal changes to the code that won't be visible to users
+  of the code.
+
+## Release note format
+
+Release notes are included in files under this `docs/release-notes.d`
+directory and have a name of `*.md`.  They will be included in the
+`release-notes.md` file, and should be formatted as a Markdown list
+entry.  (A script will be developed to collect these, ordered by when
+the commits were added to the tree.)
+
+Choose a filename that is related to what this change does.  The names
+are not used for anything in particular, but to keep the files
+distinct so that there isn't a concern with merge conflicts as
+different pull requests merge in different orders.

docs/release.md

@@ -24,6 +24,12 @@ Before making a release, update the `docs/release-notes.md` file
 to describe the release. This should be a high-level description of
 the changes, not a list of the git commits.
 
+Provided that changes going into the release have followed the
+contribution guidelines, this should mostly consist of collecting the
+various snippets in the `docs/release-notes.d` directory.  After
+incorporating these snippets into the release notes, the snippet files
+should be removed to ready the directory for the next release cycle.
+
 ## Release candidates
 
 Before each release, tags are made (see below) for at least one