In README file we're refferencing plugins repo for installing
config_template from it. However, we're using module from it's
collection.
We're updating documentation along with renaming a-r-r to more common
requirements.yml and adjusting rc file
to drop not required overrides from there.

Change-Id: I7bf4c0fca678fd50be2dc041fe16efcc67c44fa5
Closes-Bug: #1961621