Fixes and updates to your nimble -repo

I've done some fixes and added a few features. Merge if Necessary.
Added:
(1) Lets the user decide the recording time and also an option to discard the recording.
(2) Saves the recording with a different filename each time (done automatically) (Format: SavedAudio[Track_Number].wav).
(3) Saves the recording in a folder called "Saved recordings"
Fixes:
Fixed a typo in playwav.py which was not letting the audio stream to be closed properly.