Add JSDocs to Universal-Federated-Analytics.js

- Add eslint-jsdoc-plugin to enforce that JSDocs exist for all linted code

Author: Michael Levin

README.md

@@ -122,8 +122,7 @@ npm install
 
 #### Linting
 
-This repo uses Eslint and Prettier for code static analysis and formatting. Run
-the linter with:
+This repo uses Eslint for code static analysis. Run the linter with:
 
 ```bash
 npm run lint