Mock script removed & README updated

Author: Guzel738

kafka-ui-react-app/README.md

@@ -24,10 +24,6 @@ If you plan to use full fake REST API you have to update `.env`.
 ```
 REACT_APP_API_URL=http://localhost:3004
 ```
-Start JSON Server if you prefer to use default full fake REST API.
-```
-npm run mock
-```
 Start application
 ```
 npm start

kafka-ui-react-app/package.json

@@ -42,7 +42,6 @@
     "lint:fix": "eslint --ext .tsx,.ts src/ --fix",
     "test": "react-scripts test",
     "eject": "react-scripts eject",
-    "mock": "node ./mock/index.js",
     "tsc": "tsc"
   },
   "husky": {