Add aur-dev to our servers list

docs/servers.md

@@ -27,6 +27,14 @@
 ### Services
   - aurweb
 
+## aur-dev.archlinux.org
+
+### Services
+  - aurweb deployed with the `pu` branch
+
+  The database is filled using the `./schema/gendummydata.py` script in the aurweb repository with a
+  modification to create suspended users. Test users can sign up using the normal registration flow.
+
 ## bugs.archlinux.org
 
 ### Services