Generate docs about lack of timeouts in stream APIs

### Describe the issue

The SDKs do not currently have any timeouts for [stream](https://smithy.io/2.0/spec/streaming.html#streaming) APIs, and it is not obvious to the customers that their application code needs to wrap calls to those APIs with explicit timeouts like `tokio::time::timeout`.

### Links

[Example for current doc on stream API](https://docs.rs/aws-sdk-ebs/latest/aws_sdk_ebs/struct.Client.html#method.get_snapshot_block) (no mentioning regarding the absence of timeouts)

The issue points to generated docs.rs stream API documentation and the Smithy streaming specification. Start by locating the documentation generator or template for methods such as GetSnapshotBlock, then update the generated API guidance to explain the lack of timeouts and the need for explicit caller-side handling such as tokio::time::timeout. Done means stream API docs clearly communicate this limitation.

Written by the indexing model from the issue text.