add latest new section to frontpage

We use a custom override template (jinja) to generate a suitable list of
new items.

Also added first text for announcing our new user docs

mkdocs.yml

@@ -3,7 +3,7 @@ site_name: HPCE User Documentation
 site_url: https://hpce.pages.psi.ch
 
 # Repository
-repo_name: hpce-userdocs
+repo_name: "User Documentation Repository"
 repo_url: https://gitea.psi.ch/hpce/gitea-pages
 # TODO unsure if this works, branch needs to be changed from `mkdocs` to `main`
 edit_uri: _edit/mkdocs/docs/
@@ -16,6 +16,7 @@ theme:
   name: material
   favicon: images/favicon.ico
   logo: images/hpce_logo.png
+  custom_dir: overrides
   features:
     - navigation.instant
     - navigation.tabs