Add React Denver to the Meetups page

Author: willklein

content/community/meetups.md

@@ -186,6 +186,7 @@ Do you have a local React.js meetup? Add it here! (Please keep the list alphabet
 * [Columbus, OH - ReactJS](https://www.meetup.com/ReactJS-Columbus-meetup/)
 * [Dallas, TX - ReactJS](https://www.meetup.com/ReactDallas/)
 * [Dallas, TX - [Remote] React JS](https://www.meetup.com/React-JS-Group/)
+* [Denver, CO - React Denver](https://reactdenver.com/)
 * [Detroit, MI - Detroit React User Group](https://www.meetup.com/Detroit-React-User-Group/)
 * [Indianapolis, IN - React.Indy](https://www.meetup.com/React-Indy)
 * [Irvine, CA - ReactJS](https://www.meetup.com/ReactJS-OC/)