[docs][glossary] add new entry for client-side rendering (#25984)
[docs][glossary] add new entry for client-side rendering (#25984)

* add new glossary entry for client-side routing

* update text to address rendering vs. routing

* Add link to page, rather than anchor

Co-authored-by: Hashim Warren <64af4db84c67a92e6c0944e1e936550a67a85901@gatsbyjs.com>
gatsbyjs/gatsby,gatsbyjs/gatsby,gatsbyjs/gatsby,gatsbyjs/gatsby,gatsbyjs/gatsby,gatsbyjs/gatsby