title: omit type aliases from scaladoc search
body: <p>I'm currently using a multi-package open source framework that exposes dozens of classes/objects as type aliases in a root package, apparently solely for the purpose of making wildcard importing easy.</p>
  <p>unfortunately, because these type aliases have the same name as the actual qualified type, they always come up first in the search function, which wastes time and valuable screen space.</p>
  <p>is there an annotation I can put in front of a type alias to stop it from showing up in search? I don't want to omit it entirely from the documentation, because it obviously isn't irrelevant, it's just that nobody would look for these aliases by name. also note that I'm generating these docs for my own personal perusal, so we <em>don't</em> need to debate whether hiding members from search is bad practice for a public framework.</p>