Add jscs's JSDocs plugin

[felquis]

Should run with gulp style-guide, package's homepage

[felquis]

I used these rules

"jsDoc": {
    "checkParamNames": true,
    "requireParamTypes": true,
    "checkRedundantParams": true,
    "checkRedundantReturns": true,
    "requireReturnTypes": true,
    "requireParamDescription": true,
    "requireHyphenBeforeDescription": true,
    "disallowNewlineAfterDescription": true,
    "requireDescriptionCompleteSentence": true,
    "enforceExistence": "exceptExports"
}

@giorgiofellipe what do you think about the result?