Expose NonEmptyTuple type

[tommy-mitchell]

Closes #420.
Closes #476.
Closes #661.

Exposes internal NonEmptyTuple type.

Matches any non-empty tuple.

import type {NonEmptyTuple} from 'type-fest';

const sum = (...numbers: NonEmptyTuple<number>) => numbers.reduce((total, value) => total + value, 0);

sum(1, 2, 3);
//=> 6

sum();
//=> Error: Expected at least 1 arguments, but got 0.

[tommy-mitchell]

Addressed comments in #906:

• Split internal.d.ts into multiple files #906 (comment)
• Split internal.d.ts into multiple files #906 (comment)
• Split internal.d.ts into multiple files #906 (comment)