added commit input in action.yaml

Signed-off-by: James Bradlee <james.bradlee@telenor.no>

action.yml

@@ -9,6 +9,11 @@ inputs:
       The branch, tag or SHA to checkout. When checking out the repository that
       triggered a workflow, this defaults to the reference or SHA for that
       event.  Otherwise, uses the default branch.
+  commit:
+    description: >
+      The commit SHA to checkout. Used when ref is not specified or is ambiguous.
+      This can be used as a replacement for ref, or alongside it to checkout a
+      specific commit of the ref.
   token:
     description: >
       Personal access token (PAT) used to fetch the repository. The PAT is configured