fix(docs,checklists): Rename section to be more descriptive

Author: marioevz

docs/writing_tests/checklist_templates/eip_testing_checklist_template.md

@@ -84,9 +84,9 @@ If the opcode contains variables in its data portion, for each variable `n` of t
 
 | ID                                                           | Description        | Status | Tests |
 | ------------------------------------------------------------ | ------------------ | ------ | ----- |
-| `opcode/test/stack_complex_operations/variable_n/top`    | Top stack item.    |        |       |
-| `opcode/test/stack_complex_operations/variable_n/bottom` | Bottom stack item. |        |       |
-| `opcode/test/stack_complex_operations/variable_n/middle` | Middle stack item. |        |       |
+| `opcode/test/stack_complex_operations/data_portion_variables/top`    | Top stack item.    |        |       |
+| `opcode/test/stack_complex_operations/data_portion_variables/bottom` | Bottom stack item. |        |       |
+| `opcode/test/stack_complex_operations/data_portion_variables/middle` | Middle stack item. |        |       |
 
 #### Execution context
 

src/ethereum_test_checklists/eip_checklist.py

@@ -201,21 +201,24 @@ class Even(ChecklistItem):
 
                         pass
 
-                class VariableN(ChecklistItem):
-                    """Variable N tests for stack manipulation."""
+                class DataPortionVariables(ChecklistItem, override_name="data_portion_variables"):
+                    """
+                    If the opcode contains variables in its data portion, for each variable `n`
+                    of the opcode that accesses the nth stack item, test `n` being.
+                    """
 
                     class Top(ChecklistItem):
-                        """Top stack item."""
+                        """`n` is the top stack item."""
 
                         pass
 
                     class Bottom(ChecklistItem):
-                        """Bottom stack item."""
+                        """`n` is the bottom stack item."""
 
                         pass
 
                     class Middle(ChecklistItem):
-                        """Middle stack item."""
+                        """`n` is the middle stack item."""
 
                         pass