(maint) Update GRM configuration

We are consolidating labels that are in use across our repositories, so
this commit brings the GRM configuration up to date.  Namely, we are
using Enhancement now, where we might have used Improvement or Feature
before.  Also, removed C4B Feature as this has never been used. Finally,
update the Internal Refactoring label to use the new `Area - Refactor`
label.

Author: gep13

gitreleasemanager.yaml

@@ -1,15 +1,12 @@
 issue-labels-include:
   - Breaking Change
   - Deprecate
-  - Feature
-  - C4B Feature
+  - Enhancement
   - Bug
-  - Improvement
   - Documentation
   - Dependency Change
 issue-labels-exclude:
-  - Internal Refactoring
-  - BuildAutomation
+  - Build Automation
   - NO RELEASE NOTES
 issue-labels-alias:
   - name:    Documentation
@@ -37,4 +34,4 @@ close:
     - [GitHub Release](https://github.com/{owner}/{repository}/releases/tag/{milestone})
     - [Chocolatey Package](https://community.chocolatey.org/packages/chocolatey/{milestone})
 
-    Your **[GitReleaseManager](https://github.com/GitTools/GitReleaseManager)** bot :package: :rocket:
+    Your **[GitReleaseManager](https://github.com/GitTools/GitReleaseManager)** bot :package: :rocket: