Parser improvements

[richardscarrott]

1. Default to { keepUnknown: true }

   
   const parser = parse.object(
   {
   firstName: parse.trim,
   lastName: parse.trim,
   // Forgot to add `age`
   },
   { keepUnknown: true }
   );

const validator = object({ firstName: string, lastName: string, age: or(nullish, number) });

// This won't error because the parser has thrown away age which most likely isn't desirable const errors = validator(parser({ firstName: 'foo', lastName: 'bar', age: 100 }));

2. Rename to just `parse`?
    - Need an ergonomic way to import validator fns vs parse fns as there's overlap in name
       - I don't expect many more (any more?) utils to be provided by parse as they're just simple fns
       - Perhaps `import * as parse from 'ok-computer/parse`?
3. Expose well typed `pipe` util?
    - [`@bitty/pipe`](https://github.com/VitorLuizC/bitty/blob/master/packages/pipe/README.md) is good, but hassle to have to install it when it's frequently needed to compose parser fns?
    - Perhaps under `ok-computer/utils` or even `ok-computer/pipe`?
4. Add docs