support for indexOf

[wyattades]

As far as I can tell, this is the exact same reasoning as .includes (and may belong in the same entrypoint)? Happy to open a PR depending on your feedback.

Example:

// BEFORE
const users = ["matt", "sofia", "waqas"] as const;

// Argument of type '"bryan"' is not assignable to
// parameter of type '"matt" | "sofia" | "waqas"'.
users.indexOf("bryan");

// AFTER
import "@total-typescript/ts-reset/array-indexof"; // or array-includes?

const users = ["matt", "sofia", "waqas"] as const;

// .indexOf now takes a string as the first parameter
users.indexOf("bryan")

[mattpocock]

Makes a ton of sense!