Remove the part in the readme about consistency as a symbol
Clarify that prepared statements should be prepared only once

[ci skip]
The batch docs in the readme introduced new concepts, move them

It makes more sense to introduce the :consistency option in one place for regular, prepared and batch statements.

Tracing will get it's own section, too.

[ci skip]
Add a readme section on tracing
Clarify the 9160 issue in the readme

[ci skip]
Make a tiny wording change in the readme

[ci skip]
Version bump to v2.0.0