remove red theme style from doc

Author: MaxenceGollier

docs/src/assets/style.css

@@ -1,10 +1,3 @@
-#documenter .docs-sidebar,
-html.theme--documenter-dark #documenter .docs-sidebar {
-  border-right: 4px solid #640000;
-  background-color: #8c1515;
-  color: #fff; 
-}
-
 .mi, .mo, .mn {
   color: #317293;
 }