Adding workflow to build frontend gallery on schedule.

.github/workflows/build.yml

@@ -0,0 +1,41 @@
+name: Build Frontend Gallery Periodically
+
+on: 
+    schedule:
+        - cron: "0 4 * * *"
+
+    workflow_dispatch:
+      
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+        with:
+            path: frontend-documentation
+            ref: gh-pages
+      - uses: actions/checkout@v4
+        with:
+            path: graylog2-server
+            repository: Graylog2/graylog2-server
+      - name: Prepare Github Pages Branch
+        working-directory: frontend-documentation
+        run: |
+          rm -r ./*
+      - name: Build Frontend Gallery
+        working-directory: graylog2-server/graylog2-web-interface/docs
+        run: |
+          yarn install
+          yarn run docs:build
+          cp -r styleguide/* $GITHUB_WORKSPACE/frontend-documentation
+      - name: Commit Results
+        working-directory: frontend-documentation
+        run: |
+          NUMBER_CHANGES=$(git status -s | wc -l)
+          if [[ $NUMBER_CHANGES -gt 0 ]]; then
+            git add -A
+            git commit -m "Update website to $SERVER_SHA"
+            git push origin gh-pages
+          else
+            echo "No changes made, skipping commit"
+          fi