Add deleteList documentation

[MAILPOET-4752]

doc/api_methods/DeleteList.md

@@ -0,0 +1,26 @@
+[back to list](../Readme.md)
+
+# Delete List
+
+## `bool deleteList(string $list_id)`
+
+This method provides functionality for deleting a new list.
+
+It returns a boolean value.
+
+## Error handling
+
+All expected errors from the API are exceptions of class `\MailPoet\API\MP\v1\APIException`.
+Code of the exception is populated to distinguish between different errors.
+
+An exception of base class `\Exception` can be thrown when something unexpected happens.
+
+Codes description:
+
+| Code | Description                                                     |
+| ---- | --------------------------------------------------------------- |
+| 5    | List does not exist                                             |
+| 18   | List id is empty                                                |
+| 20   | List cannot be deleted because it’s used for an automatic email |
+| 21   | List cannot be deleted because it’s used for a form             |
+| 22   | The list couldn’t be deleted from the database                  |