[ADD] CSS cursor classes docs

docs/development/custom/aa-framework.md

@@ -0,0 +1,11 @@
+# AA Framework
+
+To establish a unified style language throughout Alliance Auth and Community Apps,
+Alliance Auth is providing its own CSS framework with a couple of CSS classes.
+
+```eval_rst
+.. toctree::
+    :maxdepth: 1
+
+    framework/css
+```