`sqlite_utils.utils.TypeTracker` should be a documented API

[simonw]

I've used it in a couple of external places now:

• https://github.com/simonw/datasette-socrata/blob/32fb256a461bf0e790eca10bdc7dd9d96c20f7c4/datasette_socrata/__init__.py#L264-L280
• https://github.com/simonw/datasette-lite/blob/caa8eade10f0321c64f9f65c4561186f02d57c5b/webworker.js#L55-L64

Refs:

• https://github.com/simonw/datasette-lite/issues/32

[simonw]

Code to document: https://github.com/simonw/sqlite-utils/blob/3fbe8a784cc2f3fa0bfa8612fec9752ff9068a2b/sqlite_utils/utils.py#L318-L331

[simonw]

I also added inline documentation and types: https://github.com/simonw/sqlite-utils/blob/773f2b6b20622bb986984a1c3161d5b3aaa1046b/sqlite_utils/utils.py#L318-L360

[simonw]

New documentation:

• https://sqlite-utils.datasette.io/en/latest/python-api.html#detecting-column-types-using-typetracker
• https://sqlite-utils.datasette.io/en/latest/reference.html#sqlite-utils-utils-typetracker