The responsive-font-size mixin documentation

[migliori]

Hello,

I just thought it was useful to report this about the documentation at https://mdbootstrap.com/docs/b4/jquery/content/responsive-font-size/

1. The PostCSS plugin link is broken
2. You should add a warning to specify that the Bootstrap $enable-responsive-font-sizes variable must be set to true in order to make it work (the default value is false)

[hiSandog]

Both points are concrete documentation fixes. The page should link to a maintained PostCSS implementation (or remove the recommendation if none is supported) and show $enable-responsive-font-sizes: true before Bootstrap is imported, since setting it afterward will not affect generated CSS. A minimal Sass snippet and expected responsive output would make the page independently verifiable.