Improve design tokens documentation

[edonehoo]

trafficstars

Follow-up to https://github.com/patternfly/patternfly-org/issues/4362

Improve the effectiveness of the all tokens page by finding a way to group tokens by concept (colors, spacers, breakpoints, etc.). This may involve breaking the current table into multiple tables, adding a type column and filter, or something else. May even mean creating a new page/section, rather than replacing our current table.

Research other design system approaches and consider user research to help understand how people currently use & want to use this page.