Fix action-trigger to also build on docs-changes

.github/workflows/merge.yml

@@ -4,7 +4,8 @@
 # - checkout gh-pages for updating
 # - create joined vocabulary file in addition to split version
 # - create excel-file from turtle
-# - build docs
+# - build pyLODE docs
+# - build sphinx docs/site
 # - publish docs, vocabulary-turtle files and excel-file to gh-pages
 
 name: Build
@@ -13,6 +14,7 @@ on:
     branches:
       - main
     paths:
+      - 'docs/**'
       - 'vocabularies/**.ttl'
   workflow_dispatch: