(gh-64) Add note to acceptance.yaml collection input for main

...to emphasis that you should use the 7.x branch to test openvox7
rather than setting collection to openvox7. Could also hard set it in
the workflow, but thought some flexibility may be better when we start
to transition to openvox9, for example.

Author: jpartlow

.github/workflows/acceptance.yaml

@@ -31,7 +31,12 @@ on:
         description: '(Version) Package version to test. (required if Pre-release Build is true)'
         type: string
       collection:
-        description: '(Collection) OpenVox collection to use. (ignored if Pre-release Build is true)'
+        description: |-
+          (Collection) OpenVox collection to use. (ignored if Pre-release Build is true)
+
+          NOTE: This should really only be set to openvox8 when
+          testing the main branch. If you need to test openvox7, you
+          should run the pipeline from the 7.x branch instead.
         default: 'openvox8'
         type: string
       artifacts-url: