Allow prettier to format .tsp (Typespec) files

[nenadfilipovic]

Hi guys, https://typespec.io/ is a nice thing and they also have prettier plugin for typespec files https://www.npmjs.com/package/@typespec/prettier-plugin-typespec, any chance we extend prettier config to support .tsp files?

I did checked around files and to me it seems pretty straightforward, if you don't have time I could provide PR. Thanks!