Fix some documentation issues, re-exports, and the type of the top-level trig functions.

Signed-off-by: Aaron Jacobs <atheriel@gmail.com>
Laid out more of the API.

Signed-off-by: Aaron Jacobs <atheriel@gmail.com>
Trying out an internal conversion method.

Signed-off-by: Aaron Jacobs <atheriel@gmail.com>