Web-audio-api

- Unified panic messages to format `<JsErrorType> - <Actual message>`
- Unified README.md and crate level docs
- Fix: minimize floating point errors in AudioBufferSourceNode currentTime calculation
- Fix: AudioParam automationRate does not instantly update on the control thread
- Fix: AudioParam better handling of non finite values in arguments
- Fix: Panic at Analyser initialization for some combinations of min/maxDecibel

- Fix BaseAudioContext onChangeState to signal device readiness
- Fix OfflineAudioContext::state is not updated when calling suspend and resume
- Fix AudioContext resume_sync, suspend_sync, close_sync now block until completion
- Added async versions of AudioContext suspend/resume/close

- Assert `AudioScheduledSourceNode` start and stop time values are valid
- Added BaseAudioContext `clearOnstatechange` and fix some event type names

- Fix AudioWorkletNode custom output channel counts

- Added async OfflineAudioContext methods: startRendering, suspend and resume
- Added sync OfflineAudioContext methods: suspend
- Added BaseAudioContext::onStateChange

- Breaking: `OfflineAudioContext::start_rendering_sync` takes `&mut` instead of `self`
- Fix panic in AudioBufferSource when supplying buffer in options
- Fix panic in Oscillator when supplying periodic wave in options
- Fix panic in AudioContext for really low sample rates
- Support up/down-mixing of all speaker layouts with 6 channels or less
- Disallow channel merger/splitter configurations with more than 32 channels