Jelly-like constants and functions

[DonaldTsang]

https://github.com/DennisMitchell/jellylanguage/wiki/Atoms

• shortcuts for 128, 250, 256, 360 etc.
• Vowels, consonants
• QWERTY array
• Slashes and brackets
• Set Union, difference and other operators
• Run-length encoding
• N-th prime

[Mr-Xcoder]

A few remarks: I don't think that the shortcuts for 128, 250 etc. are useful because they're going to be 3 bytes anyway. Constants for vowels and consonants might indeed be nice, especially if two versions are included, one considering y a vowel and the other way around. IMO QWERTY isn't really needed, the same goes for slashes and brackets. Set difference already exists, but other set operators would be cool indeed. RLE already exists as r8. Prime-related functions were always kind of missing in Pyth, so IMO Pyth would benefit from their addition indeed. However, I'm not sure whether there are enough characters and overloads left unused to implement them.

[DonaldTsang]

@Mr-Xcoder perhaps you could help me evaluate which ones are worth it and which aren't