Validate JSDoc argument number

[ntadej]

Validate if argument is required or not in JSDoc.
For example:

    /**
     * Return string based on error code
     * @param {number} id - error id
     * @param {string=} message - error message
     * @return {string} localized error string
     */
    error(id, message) { ... }

Here, error() should be marked as invalid, as id is required, whereas error(5) would be valid.

[angelozerr]

I agree that it should be cool if we have this feature which looks like #32 (comment)

I must study if tern can manage very well optional parameter to avoid having a lot of errors.