chore: setup codecov and badges

.github/workflows/main.yml

@@ -29,3 +29,6 @@ jobs:
 
       - name: ▶️ Run build script
         run: npm run build
+
+      - name: ⬆️ Upload karma coverage report
+        uses: codecov/codecov-action@v2

README.md

@@ -1,6 +1,17 @@
 Universal Serialize
 -------------------
 
+[![build status][build-badge]][build]
+[![code coverage][coverage-badge]][coverage]
+[![npm version][version-badge]][package]
+
+[build-badge]: https://img.shields.io/github/workflow/status/krakenjs/universal-serialize/build?logo=github&style=flat-square
+[build]: https://github.com/krakenjs/universal-serialize/actions?query=workflow:build
+[coverage-badge]: https://img.shields.io/codecov/c/github/krakenjs/universal-serialize.svg?style=flat-square
+[coverage]: https://codecov.io/github/krakenjs/universal-serialize/
+[version-badge]: https://img.shields.io/npm/v/universal-serialize.svg?style=flat-square
+[package]: https://www.npmjs.com/package/universal-serialize
+
 Universal serializer and deserializer, which supports many build-in javascript types, and any number of custom types you want to support
 
 ## Simple serialization