adding semantic ui to react code example

Example 1: semantic ui react npm install

npm install semantic-ui-react

Example 2: install semantic ui react

React components can be installed via yarn or npm:
npm install semantic-ui-react semantic-ui-css
##After install, import the minified CSS file in your app's entry file:
import 'semantic-ui-css/semantic.min.css'
#Themes from Semantic UI >=2.3.x require Semantic UI React >=0.81.0.