Add more detail to docs

docs/development/custom/framework/datatables.md

@@ -121,6 +121,24 @@ Given the `EveCharacter` Model as our model of choice we would define our stubs
 
 Then we can setup out view in our `appname/views.py` file.
 
+### Columns definition
+
+The `columns` must be defined as a 2 part tuple
+
+- Part 1 is the database field that will be used for filtering and ordering. If this is a foreign key you need to point to a field that is compatible with `__icontains` like `charField` or `textField`. It can be `None`/`False`/`""` if no ordering for filtering is required for this row.
+  - Examples for the EveCharacter Model:
+    - `character_name`
+    - `character_ownership__user__username`
+    - `character_ownership__user__profile__main_character__character_name`
+- Part 2 is a string that is used to the render the column for each row. This can be a html stub or a string containing django style template language.
+  - Examples for the EveCharacter Model
+    - `{{ row.character_name }}`
+    - `{{ row.character_ownership.user.username }}`
+    - `{{ row.character_ownership.user.profile.main_character.character_name }}`
+    - `appname/stubs/character_img.html`
+
+### appname/views.py
+
 ```python
 from django.shortcuts import render
 # Alliance Auth