MDN Changelog for June 2018

Our monthly changelog documents what happened in June to the code, data, and tools that support MDN Web Docs site. The team shipped 100+ HTML interactive examples in June. They additional shipped tweaks and fixes by merging 252 pull requests, including 32 pull requests from 26 new contributors. Finally, the team shipped Django 1.11 and laid the groundwork for a variety of performance enhancements that will roll out in July and beyond.