Fixes #20550.

Fixes #20600.

- Remove margin-bottom override in favor of .mb-0 utility class
- Apply the input line-height styles to match
- Remove the min-height to match the input

Fixes #20688

[ci skip]

Change `hidden-sm-up` to `hidden-md-up` as the clearfix divs should be visible on both `xs` and `sm` devices (widths of 6 columns).

* descriptions for getting started pages

* descriptions for layout

* add content page descriptions

* more descriptions, updates to some existing ones

* correct site url

* add social stuff to config for twitter cards

* add twitter meta tags; use large image for homepage and regular card for all others

* add the assets

* more site config

* more social shiz to partial, remove existing meta for the partial, remove page title from homepage for simpler if statements