Realtimestt

- added [example](https://github.com/KoljaB/RealtimeSTT/tree/master/example_browserclient) how to realtime transcribe from browser microphone
- large-v3 whisper model now supported (upgrade to faster_whisper 0.10.0)
- added feed_audio() and use_microphone parameter to feed chunks

- Bugfix for Mac OS Installation (occured int the context of multiprocessing with the usage of queue.size(), changed to use multiprocessing.Manager().Queue() which should work under Mac)
- KeyboardInterrupt handling (we can now abort the recorder with CTRL+C)
- Bugfix for spinner handling (could lead to exception in some cases, AttributeError: 'NoneType' object has no attribute '_interval')

Implements context manager protocol. This enables the recorder instance to be used in a `with` statement, ensuring proper resource management. Waits for transcription process to start in constructor now. Fixed bug in the shutdown method.

Bugfix for a problem with the detection of short speech right after a sentence detection. In this case the voice activity detection of the new sentence overlaps with the transcription of the last sentence causing problems due to the pythons global interpreter lock mechanism. This only happens when this overlapping occurs within the same process context so that this multiprocessing upgrade should solve the issue.