Add esp idf build workflow

.gitea/workflows/build.yaml

@@ -0,0 +1,16 @@
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+
+    steps:
+    - name: Checkout repo
+      uses: actions/checkout@v2
+      with:
+        submodules: 'recursive'
+    - name: esp-idf build
+      uses: espressif/esp-idf-ci-action@v1
+      with:
+        esp_idf_version: v4.4
+        target: esp32s2
+        path: 'esp32-s2-hmi-devkit-1/examples/smart-panel'