Add `Generic Setup` term in Glossary

[acsr]

The term is used but not explained or covered in the Plone 6 Documentation except to be mentioned in the Upgrade Docs and Glossary descriptions.

Challenge

You cannot figure out easily in the Plone 6 Docs if the Generic Setup technology is still relevant for setting up a modern Volto based Plone Setup, which it in fact it is.
Especially for configuring ClassicUI features still relevant but not configureable TTW via Volto.

Example:

Portal Actions as term is only mentioned in the Plone 6 Docs for the backend and the API:
Portal Actions are touched here
https://6.docs.plone.org/backend/portal-actions.html (ZMI or ClassicUI)
https://6.docs.plone.org/plone.restapi/docs/source/endpoints/actions.html (API)

It is difficult to get a clue that this needs knowledge of Generic Setup and where to look up.

Benefit of adding terms not yet covered in the docs

The Glossary is a good starting point to be found in the docs even if not covered there.
You can safely point to older docs or related terms to catch up (like CMF Action)

Related: Point to the location in the developer stack

I would like to have some visualisation of topics in context similar to:

• https://6.docs.plone.org/conceptual-guides/package-dependencies.html#detailed-view-of-the-architecture
• https://6.docs.plone.org/conceptual-guides/package-dependencies.html#the-space-on-top-of-products-cmfplone

I would not clutter the docs with the imagery bit offer it on hover or via toggles.

One last related thing

If there is a policy what to cover in the glossary or not, I simply ignored that.

[stevepiercy]

Consider saving yourself some time and effort by first checking the issue tracker for open issues. Closing as duplicate of #1754

[acsr]

@stevepiercy Search the docs flow wiped out a demand to search issues first. Nevertheless using the Glossary to point to existing docs that will not receive a lift was the main target of the ticket.