Add type declaration

[Zen-cronic]

Motivation

The current type declaration on DefinitelyTyped of this package does not accurately reflect the function's return type. See here.

Why

The most recent version of this function (as well as the oldest ones) is not designed to return just the boolean type. In the return line, it can either return:

• false if the first or third operand is false.
• undefined if the second operand is undefined.
• whatever is exported from require() of the last operand, given all the previous values are truthy.

[sindresorhus]

Thanks for creating a TypeScript definition. 🙌 Can you follow this styleguide and also add doc comments?

Some examples:

• sindresorhus/filled-array@aae7539
• https://github.com/sindresorhus/write-json-file/blob/main/index.d.ts
• https://github.com/sindresorhus/delay/blob/main/index.d.ts

[Zen-cronic]

on it, thanks for letting me know

[Zen-cronic]

the builds are failing for nodejs v12 and below after i added the latest version of tsd 0.31.1