Making of LLemMings

Implement missing actions used by keybinds

ChatGPT: 2 prompts below

Human: Some minor tweaks were thrown in as well.

>>> Prompt 1:
Given Javascript and an array called 'lemmings' containing lemming objects.

A lemming object has the following attributes:
- isSpawned
- isDead
- rescued
- isSelected

I want three functions:

At most, one lemming can be selected at any given time. But obviously there might
be situations where no lemmings are selected.

A lemming can only be selected if it is spawned
A lemming can NOT be selected if it is dead or rescued.

Don't use any global properties, use only 'isSelected' to determine whether a
lemming is selected.

Important: If selecting next or previous go past array bounds, loop around
to select either first or last of the array (provided the spawned/dead/rescued
attributes are okay).

This time I don't need an explanation, just give me the code.

>>> Prompt 2:
In javascript, give me a function to capitalize the first letter of a string