Expose async client

[LifeJiggy]

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PR Title: Expose AsyncClient at package level for easier access

Description:

This PR makes the asynchronous DigitalOcean client more accessible by exposing AsyncClient at the main package level, improving the developer experience for users who want to use async operations.

Problem:

Previously, users had to import the async client using a longer import path:

from pydo.aio import Client  # Less intuitive

Solution:

Now users can import the async client directly from the main package:

from pydo import AsyncClient  # More intuitive and consistent

Changes Made:

1. Updated src/pydo/aio/__init__.py:

• Added AsyncClient = Client alias for the async client class
• Added "AsyncClient" to the __all__ list for proper exposure

2. Updated src/pydo/_patch.py:

• Imported AsyncClient from the aio module
• Added "AsyncClient" to the __all__ list to expose it at package level

Usage Examples:

Before (still works):

from pydo.aio import Client

async def main():
    client = Client(token="your-token")
    # ... async operations

After (new and improved):

from pydo import AsyncClient

async def main():
    client = AsyncClient(token="your-token")
    # ... async operations

Backward Compatibility:

• ✅ All existing imports continue to work
• ✅ No breaking changes
• ✅ The pydo.aio.Client import still functions

Testing:

• Import test passed: from pydo import AsyncClient works correctly
• Existing functionality remains unaffected

Files Changed:

• src/pydo/aio/__init__.py - Added AsyncClient alias and exposure
• src/pydo/_patch.py - Imported and exposed AsyncClient at package level

Impact:

• Improved DX: More intuitive import path for async operations
• Consistency: Matches the pattern of from pydo import Client for sync operations
• Zero Risk: Purely additive change with no breaking changes

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This makes async usage much more discoverable and user-friendly! 🚀