a note about how to not use gii

docs/guide/gii.md

@@ -18,8 +18,16 @@ Add these lines to your config file:
 How to use it
 -------------
 
+TBD
+
+> Note: The code generated by gii is only a template that has to be adjusted to your needs. It is there
+  to help you create new things quickly but it is not something that creates ready to use code.
+  We often see people using the models generated by gii without change and just extend them to adjust
+  some parts of it. This is not how it is ment to be used. Code generated by gii may be incomplete or incorrect
+  and has to be changed to fit your needs before you can use it.
+
 Creating your own templates
 ---------------------------
 
-TDB
+TBD