Support for ESnext Class Feature

Hello,

Curious if support for [ESnext classes](https://github.com/tc39/proposal-class-fields) is can be expected now that the feature has been [moved from stage-2 to stage-3](https://github.com/tc39/proposal-class-fields/commit/5a4ff5fa4bf30885188279f6fb8070f2e1903c32).

If not, at what point (if any) will this feature be included?

Currently using the work around detailed in https://github.com/airbnb/javascript/issues/589.

Thank you

Read the linked TC39 class-fields proposal and the Airbnb JavaScript issue 589 workaround first. The issue does not name files, tests, or an entry point, so determine which style-guide rules or documentation would be affected and clarify the expected support and acceptance criteria before starting.

Written by the indexing model from the issue text.