Update mkdocs version

By using python 3.11, we get a performance improvement. It now takes ~6 minutes to generate the page, as opposed to ~9!

docs/stylesheets/extra.css

@@ -80,6 +80,12 @@
   }
 }
 
+.md-nav__title {
+  background: unset !important;
+  box-shadow: unset !important;
+  color: white !important;
+}
+
 .md-header-nav__button.md-logo img {
   width: 1.5rem;
   height: 1.5rem;
@@ -192,4 +198,5 @@
 .news_date {
   margin-top: 3em !important;
   margin-bottom: -2em !important;
+  font-weight: bold !important;
 }