RELEASE-PROCEDURE: how to do a trurl release

Maybe with a checklist we can avoid repeating some mistakes...

RELEASE-PROCEDURE.md

@@ -0,0 +1,24 @@
+trurl release procedure - how to do a release
+==============================================
+
+in the source code repo
+-----------------------
+
+- edit `RELEASE-NOTES` to be accurate
+
+- edit `version.h` to contain the correct version
+
+- make sure all relevant changes are committed on the master branch
+
+- tag the git repo in this style: `git tag -a trurl-[version]` -a annotates
+  the tag
+
+- push the git commits and the new tag
+
+- Go to https://github.com/curl/trurl/tags and edit the tag as a release
+  Consider allowing it to make a discussion post about it.
+
+celebrate
+---------
+
+- suitable beverage intake is encouraged for the festivities