ignore workflow if that is documentation updates. (#26)

Signed-off-by: Tomoya.Fujita <[email protected]>

.github/workflows/build.yml

@@ -4,8 +4,14 @@ name: build
 on:
   push:
     branches: [ "master" ]
+    # Only kick workflow if implementation or configuration updates
+    paths-ignore:
+      - 'document/**'
   pull_request:
+    # Only kick workflow if implementation or configuration updates
     branches: [ "master" ]
+    paths-ignore:
+      - 'document/**'
 
   # Allows you to run this workflow manually from the Actions tab
   workflow_dispatch: