Update readme gif links (#7849)

Author: cchanxzy

README.md

@@ -23,7 +23,7 @@ Then open [http://localhost:3000/](http://localhost:3000/) to see your app.<br>
 When you’re ready to deploy to production, create a minified bundle with `npm run build`.
 
 <p align='center'>
-<img src='https://cdn.rawgit.com/facebook/create-react-app/27b42ac/screencast.svg' width='600' alt='npm start'>
+<img src='https://cdn.jsdelivr.net/gh/facebook/create-react-app@27b42ac7efa018f2541153ab30d63180f5fa39e0/screencast.svg' width='600' alt='npm start'>
 </p>
 
 ### Get Started Immediately
@@ -104,7 +104,7 @@ The page will automatically reload if you make changes to the code.<br>
 You will see the build errors and lint warnings in the console.
 
 <p align='center'>
-<img src='https://cdn.rawgit.com/marionebl/create-react-app/9f62826/screencast-error.svg' width='600' alt='Build errors'>
+<img src='https://cdn.jsdelivr.net/gh/marionebl/create-react-app@9f6282671c54f0874afd37a72f6689727b562498/screencast-error.svg' width='600' alt='Build errors'>
 </p>
 
 ### `npm test` or `yarn test`

docusaurus/docs/getting-started.md

@@ -23,7 +23,7 @@ Then open [http://localhost:3000/](http://localhost:3000/) to see your app.
 When you’re ready to deploy to production, create a minified bundle with `npm run build`.
 
 <p align='center'>
-<img src='https://cdn.rawgit.com/facebook/create-react-app/27b42ac/screencast.svg' width='600' alt='npm start' />
+<img src='https://cdn.jsdelivr.net/gh/facebook/create-react-app@27b42ac7efa018f2541153ab30d63180f5fa39e0/screencast.svg' width='600' alt='npm start' />
 </p>
 
 ### Get Started Immediately
@@ -118,7 +118,7 @@ Runs the app in development mode. Open [http://localhost:3000](http://localhost:
 The page will automatically reload if you make changes to the code. You will see the build errors and lint warnings in the console.
 
 <p align='center'>
-<img src='https://cdn.rawgit.com/marionebl/create-react-app/9f62826/screencast-error.svg' width='600' alt='Build errors' />
+<img src='https://cdn.jsdelivr.net/gh/marionebl/create-react-app@9f6282671c54f0874afd37a72f6689727b562498/screencast-error.svg' width='600' alt='Build errors' />
 </p>
 
 ### `npm test` or `yarn test`