feat(misc): separate CSSVariables into its own tab

[kmcfaul]

Authored by Cursor AI, pending more review for cleanliness

[patternfly-build]

Preview: https://pf-org--pr-5046-site.surge.sh

[mcoker]

Some pages on org are so slow and this PR improves them quite a bit. A before/after of DOM nodes for a few components pages that are particularly slow

component	before	after
tabs	13579	5324
table	18111	9469
button	28847	3558

[rebeccaalpert]

This looks good to me.

For pages with more than one table like http://localhost:8003/components/alert/css-variables, we may want to add a TOC or something so it's easier to see, but that's a scope increase here.

[mcoker]

I'm noticing extra filter boxes on some components. Looks like it's referencing the cssPrefix metadata in example files to build the table from? If so, we could just go through our example files and fix ones with incorrect values, and/or we could exclude the heading/table if the table is empty.

https://pf-org--pr-5046-site.surge.sh/components/button/css-variables#prefixed-with-pf-d-button

• https://github.com/patternfly/patternfly/blob/cfe5a9e62bbfaa7852e08f741a527fad63d2a1de/src/patternfly/demos/Button/examples/Button.md?plain=1#L4

https://pf-org--pr-5046-site.surge.sh/components/table/css-variables#prefixed-with-pf-c-table

• https://github.com/patternfly/patternfly-react/blob/1e942d80aa3715e39c370cb370c9aced072db4e2/packages/react-table/src/deprecated/components/Table/examples/Table.md?plain=1#L3