[DOC] Update the projects lists (#2146)

* remove Theta

* projects

* draft

* add some papers

* update papers

* update projects

* remove completed projects

* remove poorly specified/out of date projects

* remove merlin projects

* restructure papers by year

* papers using aeon

* projects list and previous projects

* update papers

---------

Co-authored-by: MatthewMiddlehurst <pfm15hbu@gmail.com>

Author: TonyBagnall

docs/contributing.md

@@ -171,7 +171,7 @@ Mentoring and Projects
 
 +++
 
-```{button-ref} mentoring
+```{button-ref} projects
 :color: primary
 :click-parent:
 :expand:

docs/index.md

@@ -293,7 +293,7 @@ examples.md
 
 contributing.md
 developer_guide.md
-mentoring.md
+projects.md
 ```
 
 ```{toctree}