Adding support for multiple @api-data annotations in a single docblock

[erunion]

This adds support for having multiple @api-data annotations within a single docblock. Previously if you wanted to document multiple datapoints, you had to do it as:

/**
 * @api-data imdb (string) - IMDB URL
 */
/**
 * @api-data trailer (string) - Trailer URL
 */
/**
 * @api-data tickets (string, BUY_TICKETS) - Tickets URL
 */

Now you can write:

/**
 * @api-data imdb (string) - IMDB URL
 * @api-data trailer (string) - Trailer URL
 * @api-data tickets (string, BUY_TICKETS) - Tickets URL
 */

As is standard with @api-data annotations, any @api-version annotation that exists within the same docblock is applied to all @api-data annotations alongside it:

// `imdb`, `trailer`, and `tickets` datapoints are now locked to version 3.0.
/**
 * @api-data imdb (string) - IMDB URL
 * @api-data trailer (string) - Trailer URL
 * @api-data tickets (string, BUY_TICKETS) - Tickets URL
 * @api-version 3.0
 */