README: in-memory database example issue with getUserByUsername

[ferdinandlist]

Tiny issue:
Usernames are always available for me using this example as a found user is returned to nowhere?

export function getUserByUsername(username: string) {
  users.forEach((user) => {
    if (user.username === username) {
      return user; // returns to nowhere as far as I can see
    }
  });
  return null;
}

The following change fixes it for me:

export function getUserByUsername(username: string): User | null {

	let foundUser = null;

	users.forEach((user) => {
		if (user.username === username) {
			foundUser = user;
		}
	});

	return foundUser;
}

[parkerdevs]

I suggest using the find method here to make the code more concise.

function getUserByUsername(username: string): User | null {
  return users.find(user => user.username === username) || null;
}