update README with npm commands

README.md

@@ -8,24 +8,24 @@ Stremio is a modern media center that's a one-stop solution for your video enter
 
 #### Prerequisites:
 * Node.js 10 or higher
-* yarn __configured for use with GitHub Packages__
+* npm 6 or higher
 
 ### Install dependencies:
 
 ```bash
-yarn install
+npm install
 ```
 
 ### Development:
 
 ```bash
-yarn start
+npm start
 ```
 
 ### Production:
 
 ```bash
-yarn build
+npm run build
 ```
 
 ## Screenshots