chore: add optional ref input

Author: OmarAlJarrah

.github/workflows/generate-docs-site.yml

@@ -20,6 +20,7 @@ jobs:
         shell: python -u {0}
         run: |
           ref = "${{ inputs.ref }}" if "${{ inputs.ref }}" != "" else "${{ github.ref }}"
+          
           with open("$GITHUB_ENV", "a") as env_file:
             print(f"TARGET_REF={ref}", file=env_file)