fix(docs): include the code repo link in the orb description

Author: matt-oakes

src/@orb.yml

@@ -1,2 +1,4 @@
 version: 2.1
-description: Orb for building and testing React Native projects
+description: |
+  Orb for building and testing React Native projects. View
+  this orb's source: https://github.com/react-native-community/react-native-circleci-orb