[Chefstyle] Mark Chefstyle repository as deprecated (#158)

Chefstyle was merged into Cookstyle in
chef/cookstyle#968, and so there's no longer a
reason to keep a separate repository. Any future fixes to the Chefstyle
configuration should be handled in the Cookstyle repository.

Once all the Chef github org repositories and major reverse dependencies on the
gem (https://rubygems.org/gems/chefstyle/reverse_dependencies) are addressed,
it can be sent to chef-boneyard.

Signed-off-by: David Crosby <dcrosby@fb.com>

README.md

@@ -4,11 +4,11 @@
 
 **Umbrella Project**: [Chef Foundation](https://github.com/chef/chef-oss-practices/blob/main/projects/chef-foundation.md)
 
-**Project State**: [Active](https://github.com/chef/chef-oss-practices/blob/main/repo-management/repo-states.md#active)
+**Project State**: [Deprecated](https://github.com/chef/chef-oss-practices/blob/main/repo-management/repo-states.md#deprecated)
 
-**Issues [Response Time Maximum](https://github.com/chef/chef-oss-practices/blob/main/repo-management/repo-states.md)**: 14 days
-
-**Pull Request [Response Time Maximum](https://github.com/chef/chef-oss-practices/blob/main/repo-management/repo-states.md)**: 14 days
+This project has been merged into
+[Cookstyle](https://github.com/chef/cookstyle) as of Cookstyle 7.32.7, where it
+can be triggered by running `cookstyle --chefstyle`.
 
 This is an internal style guide for chef ruby projects (chef-client,
 ohai, mixlib-shellout, mixlib-config, etc).