Add search index documentation

[lbboe]

Overview

Add documentation about using search indexes to query a database using Lucene Query Parser Syntax.

GitHub issue number

#417

[wohali]

This is a great contribution for the search index documentation. Thank you for your work! I left a few small comments.

Unfortunately, the actual API reference for the new endpoint /_search_analyze is missing. (I skimmed, there may be more, but I think this is the only one.) The reference can remain, but it should be broken out and described with the proper syntax as a new server-level endpoint somewhere inside src/api/server/common.rst.

We overlooked doing this for Mango and it's still a problem (we don't properly document the /_explain and /_find endpoints.) Let's not make the same mistake with Search.

[kocolosk]

I just added some documentation of the config settings for Dreyfus in the main PR that probably makes sense to include over here: apache/couchdb@0d32708

[kocolosk]

LGTM, thanks @lbboe !

[kocolosk]

Actually, found a couple of additional nits, almost there!

[kocolosk]

OK now with actual comments included 😄

[wohali]

Many of my comments from last time are still unaddressed. Please resolve.

[kocolosk]

@wohali hmm I thought the Clouseau fallout and the analyzer list were resolved. You’re definitely right about the geo one, though.

[wohali]

@kocolosk mostly, it's the lines-too-long stuff. I think our automated checker isn't faulting the source on it right now, but invariably, it will start doing so as soon as it hits master ;)

[kocolosk]

That’s weird. The linter was definitely faulting too-long-lines earlier in the PR, and Lora fixed everything it was complaining about. I’ll take a look

[kocolosk]

make check runs clean locally, fwiw

[wohali]

Looking much better, one minor change and one content shuffle still required.

[kocolosk]

OK, I think this is ready to merge, all requested changes have been made and I'm personally happy with the layout and organization of the User Guide and the additions to the API Reference. Thanks @lbboe for this contribution and thanks @flimzy and @wohali for the marathon review!