Improvement/metadata on jsonapi render

[idlechara]

Currently there is no way to pass top-level meta objects in the current implementation as it only filters for pagination options, record_count and page_count.

This line allows to jsonapi_render to include top-level meta information in the following way:

jsonapi_render json: MyResource.first, status: :ok, options: { meta: { author: "Erik Regla", pls_approve_dis: "true" } } 

[npendery]

Any hold up on this change. It would be very useful!

[npendery]

Not sure if data[:meta] has record counts already, but id maybe merge the two instead of assigning

[kceb]

Suggested change

	data[:meta] = options.fetch(:meta, {})
	data[:meta] = data.fetch(:meta, {}).merge(options.fetch(:meta, {}))

[kceb]

@tiagopog could we add this? It would be very useful