Crockford's Base32 encoding

some nice resources:

http://www.crockford.com/base32.html
https://www.youtube.com/watch?v=aUdKd0IFl34
https://www.asciitable.com/

Trying to implement a character encoding, read about this one in the book "API Design Patterns" - chpt. 6 "Resourse identification", p. 92

notes

• this implementation could include more validation
• this implementation relies on string manipulation, could probably be done more efficiently

requirements

• all letters in the encoding output must be capitalized, therefore only letters that are capitalized are valid input to the decoding method

• checksum is automatically added and checked