In handbooks, allow for tables to have sticky columns and rows

[jorbin]

Originally from: ​ https://core.trac.wordpress.org/ticket/60289

The table that shows what level of support WP has for various PHP versions is way too large for the viewing area. For example, if you scroll to see PHP 8.1, the column that lists WP versions is no longer visible.

​ https://make.wordpress.org/core/handbook/references/php-compatibility-and-wordpress-versions/

I'm not sure what easy fixes might be possible with the formatting tools, such as "freezing/stickying" the row/column headers, or expanding the viewable area, etc.

[coffee2code]

In thirteen thousand seven hundred and nineteen :

Breathe: Add styles to allow a table to have a sticky first column.

Props jorbin, coffee2code.
Fixes #7413 .