New Feature: Generate JSDoc

[Sevin777]

Add a feature that generates a JS doc outline for an existing function

function test(a,b){
    return a*b;
}

Should generate:

/**
 * @returns {number} {description}
 * @param {number} a - {description}
 * @param {number b - {description}
 */

The result should use Ace's snippets feature (generate a dynamic snippet example). Each {description} placeholder is part of the snippet. Use tern to infer type, and if type cant be inferred then make type part of the snippet;

There is already an existing extension for Brackets that does something like this, so check it out first.