add CI build

.forgejo/workflows/build.yml

@@ -0,0 +1,22 @@
+on:
+  push:
+    branches:
+      - main
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout repo
+        uses: actions/checkout@v4
+      - name: Login to Docker Hub
+        uses: https://github.com/docker/login-action@v3
+        with:
+          registry: git.zio.sh
+          username: ${{ secrets.REPO_USER }}
+          password: ${{ secrets.REPO_PASS }}
+      - name: Set up Docker Build Push Action
+        uses: https://github.com/docker/build-push-action@v2
+        with:
+          tags: git.zio.sh/astra/bsky2tg:latest
+          push: true
+          load: false