[root] [chore] [ENG-1083] update eslint config to enforce comment width to 80 characters

Summary:
Use max-len rule. Code value in the config is default 80 and there's no way to turn it off. Hacking it with length of 420.

https://eslint.org/docs/rules/max-len

https://linear.app/comm/issue/ENG-1083/eslint-rule-for-80-char-width-comments

Test Plan: you should see errors when running yarn eslint

Reviewers: ashoat, atul, palys-swm, def-au1t

Reviewed By: ashoat, atul

Subscribers: Adrian, karol-bisztyga, yayabosh

Differential Revision: https://phabricator.ashoat.com/D3918