Add Guidelines on Branch Usage

Author: jzheaux

CONTRIBUTING.adoc

@@ -0,0 +1,10 @@
+= Contribution Guidelines
+
+Development work for a given generation happens on the appropriate `releases/vX` branch.
+That is, if you are working on a maintenance release for the `1.0.x` generation, then make your commits on the `releases/v1` branch.
+Following that, perform a forward-merge to any subsequent `releases/vY` branches and finally to `main`.
+
+If you are working on the next major, commit your changes to `main`.
+
+When a version is released, it is merged from `releases/vX` to `vX`.
+This allows consumers of actions and workflows to use the `@v1` syntax whlie still having a stable usage experience.

RELEASE.adoc

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+= Release Guidelines
+
+A release happens on the appropriate `releases/vX` branch.
+That is, when releasing `v1`, release from `releases/v1` using the "Build and Deploy" action.
+
+Then forward-merge using `-s ours` from `releases/vX` to each subsequent `releases/vY` branch and finally `main`.
+When complete, merge the `releases/vX` branch into the `v1` branch.