Add initial version of CONTRIBUTING.md

CONTRIBUTING.md

@@ -0,0 +1,69 @@
+# Contributors Guide
+
+
+### dfmt follows the neptune versioning scheme 
+
+The following is taken verbatim from
+https://github.com/sociomantic-tsunami/neptune/blob/master/doc/library-contributor.rst
+
+
+## Submitting Pull Requests
+
+When making a PR to a Neptune-versioned library, the choice of which branch to
+submit a PR against is important. A branch should be chosen as follows:
+
+* If your change is a bug fix, the PR should be submitted against the oldest
+  supported minor branch.
+* If your change is a new feature, refactoring, or deprecation, the PR should be
+  submitted against the oldest supported major branch.
+* If your change is a breaking change to the API, the PR should be submitted
+  against the next unreleased major branch. 
+  (In case the v1.0.0 has not been reached this is void)
+
+
+## Major and Minor Releases
+
+When making a commit to a Neptune-versioned library, API-affecting changes
+should be noted in a file in the ``relnotes`` folder, as follows. When the
+corresponding branch is released, the files in that folder will be collated to
+form the notes for the release.
+
+The following procedure should be followed:
+
+1. Look at each commit you're making and note whether it contains any of the
+   following:
+
+   * Breaking changes to user-available features (i.e. to the library's API).
+   * New user-available features.
+   * Deprecations of user-available features.
+
+2. For each change noted in step 1, write a description of the change. The
+   descriptions should be written so as to be understandable to users of the
+   library and should explain the impact of the change, as well as any helpful
+   procedures to adapt existing code (as necessary).
+
+   The descriptions of changes should be written in the following form:
+
+     ### Catchy, max 80 characters description of the change
+
+     `name.of.affected.module` [, `name.of.another.affected.module`]
+
+     One or more lines describing the changes made. Each of these description
+     lines should be at most 80 characters long.
+
+3. Insert your descriptions into files in the library's ``relnotes`` folder,
+   named as follows: ``<name>.<change-type>.md``:
+
+   * ``<name>`` can be whatever you want, but should indicate the change made.
+   * ``<change-type>`` should be one of: ``migration``, ``feature``,
+     ``deprecation``.
+   * e.g. ``add-suspendable-throttler.feature.md``,
+     ``change-epoll-selector.migration.md``.
+
+   Normally, you'll create a new file with the selected name, but it's also ok
+   to add further notes to an existing file, if the new changes fall under the
+   same area. It is also sometimes possible that a change will require the
+   release notes for a previous change to be modified.
+
+4. Add your release notes in the same commit where the corresponding changes
+   occur.