Add support for .cjs files

[lukebmay]

In settings, the file extension .cjs is not on the list of supported extensions. The extension has become a standard for common js files.

[junderw]

A new release with cjs support has been tagged and published to apm

https://github.com/atom/language-javascript/tree/v0.134.2
https://atom.io/packages/language-javascript

However, inside Atom itself, when I click check for updates, it says no updates and my package is stuck on v0.134.1

I wonder why...

[attekemppila]

I wonder why...

... because atom/atom#23122 (Also filed by @junderw. Just linking it as a public service.)