RSocket Flowable for JavaScript

rsocket-flowable provides a JavaScript implementation of the ReactiveStreams specification, forming a core component of the `rsocket-js` monorepo. It defines fundamental interfaces and types for reactive programming, such as `Flowable`, `Single`, `ISubscriber`, and `ISubscription`, crucial for building non-blocking, asynchronous data pipelines with backpressure. The package is currently in an early alpha state, with the latest version being `0.0.29-alpha.0`. The `rsocket-js` project, and consequently `rsocket-flowable`, has an active but pre-stable release cadence, with frequent alpha updates. Its primary differentiator is its role in enabling the RSocket protocol's Reactive Streams semantics over various transports, providing fine-grained control over data flow and resource management through explicit backpressure.