https://github.com/gcanti/fp-ts/blob/master/docs/modules/ReaderEither.ts.md#local-function

I am not sure why it is used.
Needs some research.

Seeing there are methods for AsyncOption, TaskResult, and even TaskResultOption, I'm surprised that there isn't a module with functions for TaskOption. Even there is a computation expression, but no module functions. Exists any reason for that?

This is an epic, will raise issues for each bit.

Any code snippets should be linked to actual code examples and ideally have something in the build that generates the wiki pages or at least validates that the examples correspond to real code. This is to prevent the documentation from becoming out of date.