Json schema for config files

[JeroMiya]

There are editors and command line validation tools that support json schema for nice auto-complete and validation of json files. It's often useful to provide a json schema when your utility takes a json file as input, as HTMLHint does with the .htmlhintrc json configuration files. I made a schema file for the .htmlhintrc file which includes HTMLHint specific options. It sets "additionalProperties" to true to allow jshint and csshint options, but doesn't include schema for them.

[JeroMiya]

Looks like the original Travis build failure was due to npm flakiness. This change just adds a non-code file, so shouldn't have affected any behavior and I was able to run the tests successfully locally. May have just been a transient npm error.

[yaniswang]

This file used for IDE?
Can you tell me, the name of ide support the Json schema.

[felixfbecker]

@yaniswang Visual Studio Code, Visual Studio, WebStorm, Atom, ...
there is also an incomplete list here: http://json-schema.org/implementations.html
@JeroMiya

• Would it be possible to reference the schemas of jshint and csshint?
• Shouldn't this PR target https://github.com/schemastore/schemastore/?

[yaniswang]

Support ide is too little!

[ArmorDarks]

Well, now when Visual Studio, Atom and WebStorm took more than half of market, I can't say that support is too little.