Merge pull request #35 from github/kh-update-readme

Update README with extension recommendation and note

Author: khiga8

README.md

@@ -56,3 +56,12 @@ linters:
 bundle install
 bundle exec rake
 ```
+
+## Recommended extension
+
+If you use VS Code, we highly encourage [ERB Linter extension](https://marketplace.visualstudio.com/items?itemName=manuelpuyol.erb-linter) to see immediate feedback in your editor.
+
+## Note
+
+This repo contains several accessibility-related linting rules to help surface accessibility issues that would otherwise go undetected until a later stage. Please note that due to the limitations of static code analysis,
+these ERB accessibility checks are NOT enough for ensuring the accessibility of your app. This shouldn't be the only tool you use to catch accessibility issues and should be supplemented with other tools that can check the runtime browser DOM output, as well as processes like accessibility design reviews, manual audits, user testing, etc.