Add support for @template JSDoc

[NoelAbrahams]

Hi, it will be useful to be able to document generic parameters:

/** The foo class.
  * @template TFirst ...
  * @template TSecond ... */
class Foo<TFirst, TSecond> {

}

var foo = new Foo< // Info

[johnnyreilly]

+1 for this

[danquirk]

This tag appears to be undocumented but supported in WebStorm for this same purpose so may be reasonable to go ahead with it (http://stackoverflow.com/questions/16017627/document-generic-type-parameters-in-jsdoc).

[kitsonk]

Carried over from #5854, it was pointed out that Closure Compiler documents this feature.

[Liero]

I'm not sure what is the final syntax for documenting generic arguments. Can you point to documentation or briefly describe, please?

[billti]

@Liero see the examples at https://github.com/Microsoft/TypeScript/wiki/JsDoc-support-in-JavaScript

[unional]

@RyanCavanaugh is it in nightly? I check and 2.1.0-dev.20160712 does not work:

The "@template T Inferred ...." is treated as part of summary.

[mhegazy]

@unional can you log a new issue with more details