* Fix indentation of code sample in document comment
* Make Whisper::Context#transcribe able to run non-parallel
* Add test for Whisper::Context#transcribe with parallel option
* Follow signature API change of Context#transcribe
* Remove useless variable assignment
* Move simple usage up in README
* Add need help section in README
* Add document on Context#transcribe's parallel option in README
* Update date
* Fix signature of Context.new
* Make Context#subscribe accept n_processors option
* Make test follow #transcribe's change
* Make RBS follow #transcribe's change
* Add document for #transcribe's n_processors option
* Rename test directory so that Rake tasks' default setting is used