DynamoDBBatchGetItemRequest has incorrect type

The type for `DynamoDBBatchGetItemRequest` includes projection as a top level attribute:
```
export type DynamoDBBatchGetItemRequest = {
operation: 'BatchGetItem';
tables: {
[tableName: string]: {
keys: Key[];
consistentRead?: boolean;
};
};
projection?: DynamoDBProjectionExpression;
};
```

But [the documentation](https://docs.aws.amazon.com/appsync/latest/devguide/js-resolver-reference-dynamodb.html#js-aws-appsync-resolver-reference-dynamodb-batch-get-item) shows it should be on the table:

```
type DynamoDBBatchGetItemRequest = {
operation: 'BatchGetItem';
tables: {
[tableName: string]: {
keys: { [key: string]: any }[];
consistentRead?: boolean;
projection?: {
expression: string;
expressionNames?: { [key: string]: string };
};
};
};
};
```

Using version 1.7.0 (the latest as-of posting).

Locate the definition of DynamoDBBatchGetItemRequest and compare its tables structure with the linked AWS AppSync documentation. Confirm that projection is represented within each table entry and update or add the relevant type coverage; done means the type matches the documented BatchGetItem request shape.

Written by the indexing model from the issue text.