DX-647 Enhance README for consistence and details

minor polish

DX-648 simplify code for ending session

bring the deleted comments back

DX-648 add functionalities: sleep, end session, random value gen

DX-648 remove tls only use mqtts

DX-648 fix format

DX-648 Enhance the code and comments

DX-633 minor rewording

DX-633 another attempt to fix format

DX-633 fix format issue

DX-633 Enhance readme with necessary info

init commit

Initial commit