docs: Add card_management tool to README

Document the new card_management tool with its two actions:
- reposition: Set learning order for new cards
- changeDeck: Move cards between decks

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: anatoly314

README.md

@@ -93,6 +93,7 @@ The `cors_expose_headers` setting controls which response headers browsers can r
 | `find_notes` | Search for notes using Anki's search syntax |
 | `notes_info` | Get detailed information about notes |
 | `add_note` | Add a new note to a deck |
+| `card_management` | Manage cards: `reposition` (set learning order for new cards) or `changeDeck` (move cards between decks) |
 | `update_note_fields` | Update fields of existing notes |
 | `delete_notes` | Delete notes from the collection |
 | `get_due_cards` | Get cards due for review |