[CI] - Fixing #205 - Try running from repo root

Author: matthew-carroll

.github/workflows/build_docs.yml

@@ -51,6 +51,7 @@ jobs:
 
       - name: Commit and push cache changes to new PR branch
         run: |
+          cd "$GITHUB_WORKSPACE"
           BRANCH_NAME="cache-updates-${{ github.run_id }}"
           
           git switch -c $BRANCH_NAME