Algolia should include categories in the search results

[jasonLaster]

Algolia has support for multiple indices, so it would be great to create a new category index that is also searched and shown alongside organizations.

This would let users search for transportation and see the category. Or search for a parent category and see the child categories.

[bloudermilk]

@jasonLaster definitely a key feature once we have the new category pages implemented.

[leventov]

I think currently important use-cases are obstructed by the lack of this (or, the lack of the ability to see subcategories from the menu). See the story shared by Juliana here. So I bumped the priority to P2.

[leventov]

Removed "on hold" label because as far as I can tell the new category pages have been implemented.