Add gitea action

.gitea/workflows/main.yaml

@@ -0,0 +1,11 @@
+name: Build and test
+on: [push]
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-go@v5
+        with:
+          go-version: '*'
+      - run: go build