更新 .gitea/workflows/demo.yaml

Signed-off-by: pengchang <changpeng94@gmail.com>

.gitea/workflows/demo.yaml

@@ -1,6 +1,9 @@
 name: Gitea Actions Demo
 run-name: ${{ gitea.actor }} is testing out Gitea Actions 🚀
-on: [push]
+on: 
+  push:
+    branches:
+      - main
 
 jobs:
   Explore-Gitea-Actions:
@@ -16,4 +19,5 @@ jobs:
       - name: List files in the repository
         run: |
           ls ${{ gitea.workspace }}
-      - run: echo "🍏 This job's status is ${{ job.status }}."
+      - run: echo "🍏 This job's status is ${{ job.status }}."
+      - run: echo "😀😀 REPO_NAME = ${{ vars.REPO_NAME}}"