Update codesandbox URL

Author: Austin Green

.github/ISSUE_TEMPLATE.md

@@ -18,7 +18,7 @@
 
 <!--
   BONUS POINTS: spin up and share an example via
-  https://codesandbox.io/s/github/zendeskgarden/react-components/tree/examples/codesandbox/garden-create-react-app or https://codesandbox.io/s/new or https://stackblitz.com/fork/react.
+  https://codesandbox.io/s/github/zendeskgarden/react-components/tree/master/examples/codesandbox/garden-create-react-app or https://codesandbox.io/s/new or https://stackblitz.com/fork/react.
 -->
 
 ### Fine Print

README.md

@@ -173,7 +173,7 @@ render(<App />, document.getElementById('root'));
 
 Try out Garden React components in a mock product environment.
 
-[![Edit Garden Create-React-App](https://codesandbox.io/static/img/play-codesandbox.svg)](https://codesandbox.io/s/github/zendeskgarden/react-components/tree/examples/codesandbox/garden-create-react-app)
+[![Edit Garden Create-React-App](https://codesandbox.io/static/img/play-codesandbox.svg)](https://codesandbox.io/s/github/zendeskgarden/react-components/tree/master/examples/codesandbox/garden-create-react-app)
 
 ## Contribution