Recent ESLint updates - BigInt, improved autofixing and more

Over the last couple of weeks we landed a couple of ESLint updates which support new features and fix a few issues. Here's a quick summary: * BigInt <https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/BigInt> is now supported. * For globals

ESlint Updates

Three quick notes about updates for things we're doing with ESlint and Firefox: 1. There's a new help page on devmo with ESLint tips & advice: https://developer.mozilla.org/docs/ESLint 2. Jared has been posting about about rules being enabled on his blog: https://msujaws.wordpress.com/ 3.