* fix#3: added h ui command to toggle ui
* fix#4: added -N flag to disable colors
* fixed styling of line numbers (-n)
* fix#5 add usage section
* add pkg/epub module readme
* add license terms to all file headers
* fixed usage printing
* added basic unit tests
* run the tests only on linux due to the use of base64 utitlity
- add color and color config support
- fix epub parsing
- add variable margin (left and right arrow keys)
- add help screen (hit `?`)
- add config file support