There’s a thread elsewhere on diacriticals. The short version is, you have to have do it based on your own operating system. We created a widget for inserting them, but it broke with an upgrade. Discourse is in the process of updating the editor, and we are waiting for this to be complete before adding the widget again.
This is all good stuff. Like on Google these days, we won’t just get a list of hits, but organized information.
FYI, we use elasticsearch (based on Lucene) for our search engine on SuttaCentral, and it was configured and maintained by @blake. He’ll be very happy to respond to any questions.