This updates documentation related to knowledge bases (formerly
known as Copilot for Docs/docsets) ahead of our upcoming GA 🎉
The way that we think about this product has changed, meaning
that I have dropped the current "Copilot docset management"
section and the "About docset management" page in favour of
folding this content into the main "Copilot Chat in GitHub.com"
articles.
"Managing knowledge bases" is still its own page, because that
*just makes sense*.
At a more granular level, this PR:
* Updates references to "docsets" to refer to "knowledge bases"
instead
* Reflects the new way to use a knowledge base in Copilot Chat,
with the "Attach knowledge" button
* Switches documentation about creating and managing knowledge
bases to point to the new home of these settings within an
organization's settings screen
* Corrects some inconsistencies in the main "About Copilot Chat
in GitHub.com" article where we refer to IDEs. We should keep
IDE chat and Dotcom chat more separate, imo, as they are
different products with different features.
For more context, see the content design plan in
https://github.com/github/docs-strategy/pull/2468.
Closes https://github.com/github/docs-content/issues/13473.
