How to Map `Caps Lock` (⇪) key to `Esc` on `Mac`?

I almost _never_ use the ⇪ "caps lock" key on my `Mac`.
I know @samhstn re-mapped his `Caps Lock` to `Esc` back-in-the day:
https://github.com/samhstn/my-config#karabiner-elements
because it was faster to use than reaching for `Esc` when using `Vim` ...

But rather than installing a key-biding/modifier program like [`Karabiner`](https://karabiner-elements.pqrs.org/),
I want to understand how to do this _natively_ (_and document the steps..._)

So I'm looking up how to do that now:
https://vim.fandom.com/wiki/Map_caps_lock_to_escape_in_macOS