Spacing sizes are a bit counter-intuitive

[entozoon]

Referring to the spacing sizes explained in:
https://v4-alpha.getbootstrap.com/utilities/spacing/

I was surprised to see that these aren't linear increments 0, 1, 2, 3, etc as might be expected by the classnames (i.e. p-3 yields 1 spacers worth, rather than 3)

but aside from that, with the pattern they currently have, it looks like they're supposed to double up each increment but they don't - the pattern being 0, 0.25, 0.5, 1, 1.5, 3 which is inconsistent.

Perhaps there's a logical reason?
If not, I've popped in a pull request for a consistent doubling up pattern 0, 0.25, 0.5, 1, 2, 4 although (in my opinion) linear increments might be better, for which I'd happily do a PR if desirable.

#21703

[Starsam80]

Duplicate of #21342.

[mdo]

Closing as dupe.