Rename "table" to "type"

[simonw]

I think "table" is the wrong name for the concept I'm using it for here.

Two reasons: firstly, table is a reserved word in SQLite. More importantly, it turns out there's not a direct mapping from tables to types of search result. In particular, for GitHub I ended up having two different "tables" of repositories - one for repos created by me, another for repos that I have starred.

[simonw]

At some point I may even want to support search types which are indexed from (and inflated from) more than one database file. I'm going to ignore that for the moment though.

[simonw]

Alternative names:

• type
• record_type
• doctype

I think type is right. It matches what Elasticsearch used to call their equivalent of this (before they removed the feature!). https://www.elastic.co/guide/en/elasticsearch/reference/current/removal-of-types.html