github: Rename GitHub workflow action

GitHub checks need to be uniquely named, and 'Documentation' conflicts
with the ci-tool name.  Rename this while we are running both so the
names don't conflict.

Signed-off-by: Kumar Gala <[email protected]>

Author: galak

.github/workflows/doc-build.yml

@@ -1,7 +1,7 @@
 # Copyright (c) 2020 Linaro Limited.
 # SPDX-License-Identifier: Apache-2.0
 
-name: Documentation
+name: Documentation GitHub Workflow
 
 on: [pull_request, push]