Redesign the playground UI (GH-24)

Author: ArtyomVancyan

.github/workflows/tests.yml

@@ -14,7 +14,7 @@ jobs:
     strategy:
       matrix:
         node-version: [ 16.x, 18.14.2, 20.x ]
-        environment: [ jest, joy_build, base_build, core_build, material_build ]
+        environment: [ jest5, jest6, jest7, joy_build, base_build, core_build, mui5_build, mui6_build, mui7_build ]
 
     steps:
       - name: Checkout

README.md

@@ -2,6 +2,7 @@
 
 [![npm](https://img.shields.io/npm/v/mui-phone-input)](https://www.npmjs.com/package/mui-phone-input)
 [![Playground](https://img.shields.io/badge/playground-blue.svg?logo=data:image/svg+xml;base64,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)](https://playground.typesnippet.org/mui-phone-input/)
+[![mui](https://img.shields.io/badge/mui-5.x%20%7C%206.x%20%7C%207.x-blue)](https://github.com/mui/material-ui)
 [![distro](https://img.shields.io/badge/distro-core%20|%20material%20|%20base%20|%20joy-blue)](https://mui.com/)
 [![types](https://img.shields.io/npm/types/mui-phone-input)](https://www.npmjs.com/package/mui-phone-input)
 [![License](https://img.shields.io/npm/l/mui-phone-input)](https://github.com/typesnippet/mui-phone-input/blob/master/LICENSE)