website: allow linking to a specific extension

[ES-Alexander]

It would be nice to be able to link to a given extension, for the purpose of sharing that it exists.

If extensions will have their own pages ideally this would just open up the extension's page, but in the interim it would be nice if it could jump to the section of the listing page where that extension's card is, and display the card as selected / highlighted / active.

Chrome's "link to highlight" tool is an existing potential solution, but it's brittle (will fail if the extension name or docker changes), and the results aren't super visually pleasing. As an example:
https://docs.bluerobotics.com/BlueOS-Extensions-Repository/#:~:text=Cerulean%20DVL,-Maintainer