:chg :doc adding section about commit formatting to docs !minor [ci-s…

…kip]

docs/contributing.rst

@@ -10,6 +10,61 @@ Code contributions
 -------------------
 Of course code contributions are welcome. Please follow the standard Github PR process.
 
+Commit format
+--------------
+We've just started using `gitchangelog <https://pypi.org/project/gitchangelog/>`__ to format git commits and generate a changelog. Please follow their example file like below:
+
+::
+
+  Format:
+
+  ACTION: [AUDIENCE:] COMMIT_MSG [!TAG ...]
+
+  Description:
+  ACTION is one of 'chg', 'fix', 'new'
+
+      Is WHAT the change is about.
+
+      'chg' is for refactor, small improvement, cosmetic changes...
+      'fix' is for bug fixes
+      'new' is for new features, big improvement
+
+  AUDIENCE is optional and one of 'dev', 'usr', 'pkg', 'test', 'doc'
+
+      Is WHO is concerned by the change.
+
+      'dev'  is for developpers (API changes, refactors...)
+      'usr'  is for final users (UI changes)
+      'pkg'  is for packagers   (packaging changes)
+      'test' is for testers     (test only related changes)
+      'doc'  is for doc guys    (doc only changes)
+
+  COMMIT_MSG is ... well ... the commit message itself.
+
+  TAGs are additionnal adjective as 'refactor' 'minor' 'cosmetic'
+
+      They are preceded with a '!' or a '@' (prefer the former, as the
+      latter is wrongly interpreted in github.) Commonly used tags are:
+
+      'refactor' is obviously for refactoring code only
+      'minor' is for a very meaningless change (a typo, adding a comment)
+      'cosmetic' is for cosmetic driven change (re-indentation, 80-col...)
+      'wip' is for partial functionality but complete subfunctionality.
+
+  Example:
+
+  new: usr: support of bazaar implemented
+  chg: re-indentend some lines !cosmetic
+  new: dev: updated code to be compatible with last version of killer lib.
+  fix: pkg: updated year of licence coverage.
+  new: test: added a bunch of test around user usability of feature X.
+  fix: typo in spelling my name in comment. !minor
+
+  Please note that multi-line commit message are supported, and only the
+  first line will be considered as the "summary" of the commit message. So
+  tags, and other rules only applies to the summary.  The body of the commit
+  message will be displayed in the changelog without reformatting.
+
 
 Testing
 --------