fixing docs render

mkdocs.yml

 # Project information
 site_name: Atomistic features package
-site_url: https://squidfunk.github.io/mkdocs-material/
+site_url: https://nomad-lab.pages.mpcdf.de/ai-toolkit/atomic-features-package/
 
 # Repository
 repo_name: atomic-features-package
@@ -29,5 +29,5 @@ markdown_extensions:
 nav:
   - Home: index.md
   - Getting started: getting_started.md
-  - Atomic features: atomicfeatures.md
+  - Atomic properties: atomicproperties.md
   - Metainfo: metainfo.md