Support for multiple types in asType

[air2]

I would like support for:

export interface IPageSizeConfig {
    /**
     * @description The number of records to return in a single page.
     * @asType number | string
     */
    page_size?: number,
}

And I do not mind to specify ["number", "string"] or some other syntax to support multiple types.
Currently it's always escaped and put directly in the type value of the JSON schema, but the JSON Schema support arrays for types so it would be great if this would be supported.

Anyway thanks for all the work so far, it's really a cool library.

[domoritz]

Makes sense. Can you send a pull request?