Add precise TypeScript definitions

[spawnia]

First of all: Thank you for this library, we are using it in a project of ours and it is working great for us.

Problem Statement

We rely heavily on static analysis through TypeScript. While lodash's omit is well-typed, omitDeep currently is not. That causes a loss of type information that makes dealing with the resulting data more difficult and error prone.

Possible Solution

In our project, we use a wrapper around omit-deep-lodash and provide type information according to https://gist.github.com/ahuggins-nhs/826906a58e4c1e59306bc0792e7826d1

import omitDeepLodash from 'omit-deep-lodash';

export function omitDeep<T, K>(
  value: T,
  key: K,
): T extends Array<any> ? DeepOmitArray<T, K> : DeepOmit<T, K> {
  return omitDeepLodash(value, key);
}

// Paste https://gist.github.com/ahuggins-nhs/826906a58e4c1e59306bc0792e7826d1 below

Next Steps

Are you generally up for providing TypeScript definitions with this library or possible even convert it to TypeScript entirely? I would be willing to provide a PR.

My proposed solution might not cover every edge case, but so far it is working for us and has improved the typing situtation in our project.