Better driver specific docs

[kpgalligan]

We mostly rely on sqldelight docs for driver config, but it really would make sense to add some better docs here. Specifically, this came up recently with encryption. See: https://github.com/touchlab/SQLiter/issues/58

I think we can add docs on the following:

• Creating a connection
• Configuration options available
• Helper functions (delete database, etc)
• Overview of linking to sqlite3
• Using encryption