message: Update README with branching model
diff: @@ -24,3 +24,20 @@ Repo Guidelines
  * The patch will be accepted if there is broad consensus that it is a good thing. Developers should expect to rework and resubmit patches if they don't match the project's coding conventions (see coding.txt) or are controversial.
  * From time to time a pull request will become outdated. If this occurs, and the pull is no longer automatically mergeable; a comment on the pull will be used to issue a warning of closure. Pull requests closed in this manner will have their corresponding issue labeled 'stagnant'.
  * For development ideas and help see [here](https://talk.peercoin.net/c/protocol).
  +
  +## Branches:
  +
  +### develop (all pull requests should go here)
  +The develop branch is used by developers to merge their newly implemented features to.
  +Pull requests should always be made to this branch (except for critical fixes), and could possibly break the code.
  +The develop branch is therefore unstable and not guaranteed to work on any system.
  +
  +### master (only updated by group members)
  +The master branch get's updates from tested states of the develop branch.
  +Therefore, the master branch should contain functional but experimental code.
  +
  +### release-* (the official releases)
  +The release branch is identified by it's major and minor version number e.g. `release-0.6`.
  +The official release tags are always made on a release branch.
  +Release branches will typically branch from or merge tested code from the master branch to freeze the code for release.
  +Only critical patches can be applied through pull requests directly on this branch, all non critical features should follow the standard path through develop -> master -> release-*
  