Do notation implementation

[apoberejnyi]

There's a technique to emulate type-safe do notation using exceptions internally.

I've provided a summary with examples in the following article: https://apoberejnyi.medium.com/do-notation-for-either-in-typescript-c207e5987b7a. Functions from there can be implemented as static methods on the Either object.

Please take a look at whether such an approach fits the library design. If so, I will be happy to contribute at least to the Maybe and Either implementations.

[ulfryk]

@apoberejnyi please see #258