add docs CI in proper location

.forgejo/workflows/docs.yml

@@ -0,0 +1,13 @@
+on:
+  pull_request:
+    types: [opened, synchronize]
+  workflow_dispatch:
+jobs:
+  test:
+    runs-on: forge-1
+    container:
+      image: registry.gitlab.com/fedora/docs/docs-website/docs-fp-o:latest
+    steps:
+      - run: microdnf -y install git tar
+      - uses: https://code.forgejo.org/actions/checkout@v6
+      - run: antora --html-url-extension-style=indexify site.yml --log-failure-level=warn