Add basic docs, remove stub get_context_data

Author: jieter

django_tables2/columns/templatecolumn.py

@@ -15,7 +15,9 @@ class TemplateColumn(Column):
     Arguments:
         template_code (str): template code to render
         template_name (str): name of the template to render
-        extra_context (dict): optional extra template context
+        context_object_name (str): name of the context variable to pas the record in, defaults to "record".
+        extra_context (dict): optional extra template context. If a callable is passed, it will be called with
+            optional record, table, value, bound_column arguments.
 
     A `~django.template.Template` object is created from the
     *template_code* or *template_name* and rendered with a context containing:
@@ -91,6 +93,3 @@ def value(self, **kwargs):
         """
         html = super().value(**kwargs)
         return strip_tags(html).strip() if isinstance(html, str) else html
-
-    def get_context_data(self, **kwargs):
-        return