Scanner

I added:

• Inline comments and doc-strings for Structs and methods.
• Changed some Wordlist methods
• Added Scanner struct and associated methods.
• Added test cases for both Wordlist and Scanner structs
• Implemented functionality to read wordlist from file.
• Implemented functionality to print color coded scan results to terminal.
• Implemented functionality to write scan results to file.
• Added helper methods for scanning functionality.

TODO:

• add timekeeping functionality
• add percent done functionality
• add scanning functionality