Add .jshintrc
Add .jshintrc

This adds a `.jshintrc` to the `linters/` directory. I just copied over
the settings from the `SublimeLinter` file, de-nesting the JSON object
by one level.

It means we'll have to maintain both files, but it's good to have a
basic `.jshintrc` for those of us that aren't using JSHint through
Sublime Text.

naustudio/javascript,codelegant/JavaScript,appcom-interactive/javascript,practicefusion/javascript,nulogy/javascript,bl00mber/javascript,whichdigital/javascript-coding-standards,xalexec/javascript,addshoppers/javascript,cloudability/javascript-style-guide,pokelondon/javascript,LodoSoftware/javascript-style-guide,naustudio/javascript,codelegant/JavaScript,ljharb/javascript,webcoding/javascript-style-guide,getjll/JavaScript-Style-Guide,airbnb/javascript,LodoSoftware/javascript-style-guide,allanfish/javascript