[UPDATE] Fixed the regular expression used to match file names

[ADD] Add download real-time progress bar

[UPDATE] Compatible with low version node

[UPDATE] Add run permissions

[UPDATE] Update screenshot

[UPDATE] Update download function

[UPDATE] Compile CoffeeScript

[UPDATE] Use color print log

[UPDATE] More friendly info display

[UPDATE] Fix a description error

[UPDATE] Update screenshot

[UPDATE] Update usage

[ADD] Add course search and options parser

[UPDATE] In the filename to replace special symbols for "_"

[UPDATE] Optimized error handling