ci(docs[temp]) Deploy from tn-color-schemes branch for FOWT live-test

why: Allow visual verification of the flash-of-wrong-theme fix at
gp-sphinx.git-pull.com before merging PR #23. The live deploy uses
the same prod S3 bucket + CloudFront distribution as main, so this
will temporarily replace production docs.

what:
- Add tn-color-schemes to docs workflow push-trigger branches
- TEMPORARY: revert this commit (or drop the line) before merging
  the FOWT fix to main

Author: tony

.github/workflows/docs.yml

@@ -4,6 +4,9 @@ on:
   push:
     branches:
       - main
+      # TEMPORARY: live-test the FOWT fix at gp-sphinx.git-pull.com
+      # before merging PR #23. Remove this entry before merge.
+      - tn-color-schemes
 
 permissions:
   contents: read