message: Add missing __ suffix to tests folder link
diff: @@ -37,7 +37,7 @@ run Jest in watch mode with:
  npm t -- --watch
  ```
  -See [`src/__tests__/example.js`](src/__tests/example.js) for an
  +See [`src/__tests__/example.js`](src/__tests__/example.js) for an
  example of how we're testing our components.
  ## Principles
  