fix: resolve MkDocs build issues

- Remove mkdocstrings reference to PositionManagerConfig type
- Keep only the code example for configuration
- This fixes the mkdocstrings import error for config_types module

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <[email protected]>

Author: TexasCoding

docs/api/position-manager.md

@@ -404,8 +404,6 @@ async def position_statistics():
 
 ### PositionManagerConfig
 
-::: project_x_py.types.config_types.PositionManagerConfig
-
 ```python
 from project_x_py.types import PositionManagerConfig