ci: improve workflow structure

.forgejo/workflows/demo.yaml

@@ -1,10 +1,22 @@
 name: Named workflow
-on: [push]
+
+on:
+  push:
+    branches: ["main"]
+
 jobs:
   test:
     runs-on: docker
+
     steps:
-      - uses: https://code.forgejo.org/actions/checkout@v4
-      - run: echo All Good
-      - run: ls -lah .
-      - run: pwd
+      - name: Setup repo
+        uses: https://code.forgejo.org/actions/checkout@v4
+
+      - name: Testing runner
+        run: echo All Good
+
+      - name: Testing local fs
+        run: ls -lah .
+
+      - name: Testing working directory
+        run: pwd