mention milestone 62 on the v2.2.0 changelog

Author: archmoj

CHANGELOG.md

@@ -69,6 +69,7 @@ where X.Y.Z is the semver of most recent plotly.js release.
  - Centralize jsdom utility to return Plotly object in node.js test scripts and use it in generating plot-schema [[#5755](https://github.com/plotly/plotly.js/pull/5755)]
  - Bump turf bbox dependency to v6.4.0 [[#5747](https://github.com/plotly/plotly.js/pull/5747)]
  - Bump turf area dependency to v6.4.0 [[#5748](https://github.com/plotly/plotly.js/pull/5748)]
+ - More maintenance work listed under [the v2.2.0 milestone](https://github.com/plotly/plotly.js/milestone/62?closed=1)
 
 ### Fixed
  - Cache values and patterns in set_convert for axes with `rangebreaks` to improve performance [[#5659](https://github.com/plotly/plotly.js/pull/5659)],