feat(eslint-plugin): add return-await rule

[drabinowitz]

This closes #994 adding the return-await rule.

[typescript-eslint]

Thanks for the PR, @drabinowitz!

typescript-eslint is a 100% community driven project, and we are incredibly grateful that you are contributing to that community.

The core maintainers work on this in their personal time, so please understand that it may not be possible for them to review your work immediately.

Thanks again!

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[drabinowitz]

@bradzacher just wanted to check in on this to see if any other info was needed from my end.

[bradzacher]

I haven't had a look, sorry - it's in the review queue, so I'll take a look soon.

[drabinowitz]

Sounds good no rush, just wanted to make sure there wasn't anything missing I needed to take care of before it was eligible for review.

[codecov]

Codecov Report

Merging #1050 into master will increase coverage by 0.01%.
The diff coverage is 96.22%.

@@            Coverage Diff             @@
##           master    #1050      +/-   ##
==========================================
+ Coverage    94.2%   94.22%   +0.01%     
==========================================
  Files         128      129       +1     
  Lines        5561     5611      +50     
  Branches     1559     1575      +16     
==========================================
+ Hits         5239     5287      +48     
  Misses        180      180              
- Partials      142      144       +2

Impacted Files	Coverage Δ
packages/eslint-plugin/src/rules/index.ts	100% <100%> (ø)	⬆️
packages/eslint-plugin/src/rules/return-await.ts	95.91% <95.91%> (ø)

[drabinowitz]

@bradzacher i wanted to check in on this pr to see if you'd had a chance to take a look at it.

[bradzacher]

I have not yet. My open source time lately has been consumed by fixing the IDE errors.
It's on the list of PRs to review.

[bradzacher]

One change, otherwise LGTM
Thanks for this.

[bradzacher]

this has to be false for now.
adding a rule to the recommended config is counted as a breaking change, so it has to wait for a major release.

(don't forget to regen configs after)

[drabinowitz]

will do!

[bradzacher]

LGTM! Thanks for this