Improve reference display

The website is full of citations that are currently not systematically linked to references - so that they are of little use. We have a standing promise to change that in the glossary (#135) but the issue also arises in many other places.

Could we fix this across the webpage? I can think of three options:

- project-specific reference pages, with links from the specific mentions
- FORRT wide reference page, with links from the specific mentions

Or, my favorite:

- when clicking on the citation, a popup appears with full reference and abstract - linking to the original source. Very simple dummy (with ChatGPT generated code) below, should of course be prettier.

[popup_test.html.zip](https://github.com/user-attachments/files/17799026/popup_test.html.zip)

@flavioazevedo would this solution make sense for you?