Prepare for branch renaming. (#367)

* Add `amd-staging` and `amd-mainline` to workflow
* Update links in documentation to use amd-mainline

---------

Signed-off-by: David Galiffi <David.Galiffi@amd.com>

.github/workflows/python.yml

@@ -3,12 +3,12 @@ run-name: Python
 
 on:
   push:
-    branches: [ main, develop ]
+    branches: [ main, develop, amd-mainline, amd-staging ]
     paths:
       - 'source/python/gui/*.py'
       - 'source/python/gui/**/*.py'
   pull_request:
-    branches: [ main, develop ]
+    branches: [ main, develop, amd-mainline, amd-staging ]
     paths:
       - 'source/python/gui/*.py'
       - 'source/python/gui/**/*.py'