add parameter to README

Author: Mike Patterson

README.md

@@ -86,6 +86,7 @@ When you run `bazel run ///helloworld:mynamespace.apply`, it applies this file i
 | ***release_branch_prefix*** | `master`     | A git branch name/prefix. Automatically run GitOps while building this branch. See [GitOps and Deployment](#gitops_and_deployment).
 | ***deployment_branch***   | `None`         | Automatic GitOps output will appear in a branch and PR with this name. See [GitOps and Deployment](#gitops_and_deployment).
 | ***gitops_path***         | `cloud`        | Path within the git repo where gitops files get generated into
+| ***app_grp***         | ``                 | Optional folder for grouping apps after gitops_path in git repo
 | ***tags***                | `[]`           | See [Bazel docs on tags](https://docs.bazel.build/versions/master/be/common-definitions.html#common-attributes).
 | ***visibility***          | [Default_visibility](https://docs.bazel.build/versions/master/be/functions.html#package.default_visibility) | Changes the visibility of all rules generated by this macro. See [Bazel docs on visibility](https://docs.bazel.build/versions/master/be/common-definitions.html#common-attributes).