docs(create_task): add quantity convention to text parameter (v0.5.2)

Documents the preferred format for quantities in shopping list tasks:
item name first, quantity in parentheses at the end.
Examples: "Äpfel (5x)", "Hackfleisch (500g)", "Joghurt (Erdbeere, 2x)".

No functional code changes.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

README.md

@@ -2,7 +2,7 @@
 
 MCP server for [Family Wall](https://www.familywall.com) -- read and manage your family's circles, lists, and tasks directly from Claude.
 
-## Features (v0.5.1)
+## Features (v0.5.2)
 
 ### Read
 
@@ -15,7 +15,7 @@ MCP server for [Family Wall](https://www.familywall.com) -- read and manage your
 
 ### Write (with confirmation prompt)
 
-- `create_task` -- create a new task in a list (supports `category_id`, `due_date`, `assignee_ids`)
+- `create_task` -- create a new task in a list (supports `category_id`, `due_date`, `assignee_ids`); use `"Äpfel (5x)"` format for quantities
 - `update_task` -- update text, description, category, due date, assignees, or move to a different list; supports `clear_due_date=True` to remove a due date
 - `toggle_task` -- mark a task complete or reopen it
 - `delete_task` -- permanently delete a task