feat: added big brain publication

[xgui3783]

Request per request from @SusanneWenzel

• adding an additional publication page under /HIBALL/publications
• update the existing publication page at /About/references to use an additional collection

please note that this is not the final version.

ping @3design , I have not updated the top nav bar (at all). As such, to see the newly added page, one will have manually type localhost:8000/publications.html

I am unsure if you have a script, or a static site generator of some kind, that generates these programmatically, so I refrained from editing the nav bar.

@SusanneWenzel , the title/menu name of the old/new page still needs to be decided.

[SusanneWenzel]

Thank you @xgui3783 I guess we have to keep titles for the menu short. I.e., I'd keep References under About, also the header and subheader on the existing page are perfectly fine. For the new page under HIBALL, I'd propose Publications as title for the menu. On the page header: HIBALL Publications subheader: Publications from the HIBALL consortium. @pjtoussaint do you agree?