Make examples notebooks more prominent on page

[canyon289]

Issue with current documentation:

The notebooks page could use a an explainer that theres more notebooks available in the examples tab. Something like

These are the core notebooks, to see even more examples go to the examples page with a link to the examples page

https://www.pymc.io/projects/docs/en/stable/learn/core_notebooks/index.html

Idea or request for content:

No response