feat: support codecov (#970)

* feat: support codecov

Author: LucasXu0

.github/workflows/flowy_editor_test.yml

@@ -37,4 +37,12 @@ jobs:
         working-directory: frontend/app_flowy/packages/appflowy_editor
         run: |
           flutter pub get
-          flutter test
+          flutter test --coverage
+
+      - uses: codecov/codecov-action@v3
+        with: 
+          name: appflowy_editor
+          env_vars: ${{ matrix.os }}
+          fail_ci_if_error: true
+          verbose: true
+

frontend/app_flowy/packages/appflowy_editor/README.md

@@ -20,6 +20,12 @@ and the Flutter guide for
     <a href="https://twitter.com/appflowy"><b>Twitter</b></a>
 </p>
 
+<p align="center">
+    <a href="https://codecov.io/gh/AppFlowy-IO/AppFlowy" >
+        <img src="https://codecov.io/gh/AppFlowy-IO/AppFlowy/branch/main/graph/badge.svg?token=YTFKUF70B6"/>
+    </a>
+</p>
+
 <div align="center">
     <img src="https://github.com/AppFlowy-IO/AppFlowy/blob/main/frontend/app_flowy/packages/appflowy_editor/documentation/images/appflowy-editor-example.gif?raw=true" width = "700" style = "padding: 100"/>
 </div>