Document how to change font size

[fulldecent]

On the documentation page https://tabler.io/docs/getting-started/customize it is advertised that you can change fonts, sizes, colors, etc.

Only one example is provided for setting a Google Font.

But there is no explanation of how to set custom font sizes.

I am guessing that maybe all of the Bootstrap customization options are supported but with a --tblr prefix. If so that's great! But it should please be documented on this page, and probably every documentation page.

At a minimum we could say on the bottom of each page:

CSS variables

You can customize the appearance of this component using CSS variables, see the Bootstrap documentation for SOME_COMPONENT and just swap in tblr any time you see #{$prefix}.