fix: exports types (#3)

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## Summary by CodeRabbit

- **Refactor**
	- Improved module exports for better usability and access to types.

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

src/client.ts

@@ -10,6 +10,7 @@ import literals from './literals';
 import channels from './channels';
 import type { ConnectionMessage, ConnectionEnqueueMessage } from './channels';
 import { RDSPoolConfig } from './PoolConfig';
+export * from './types';
 
 interface PoolPromisify extends Omit<Pool, 'query'> {
   query(sql: string): Promise<any>;