main: Move parsing code to parse.py

Implement just enough parser to do a hello world

main: Add initial parser ...

This is very messy and incomplete code, but it's a start.

main: Skip parsing shebang if detected

main: Lowercase tokens and add special keyword type

code.txt: Remove useless done

code.txt: Add copyright information

code.txt: Add NewLang statement ...

This will be used to identify the file as source code and support
forwards and backwards compatibility with future features.

main.py: Support running using a shebang

code.txt: Replace 'Done' with 'EndIf' and 'EndSet' ...

This is much less ambiguous to humans the parser.

code.txt: Switch from 'Is' syntax to 'Set To' ...

'Subject Is Command' is hard to distinguish from 'Subject Verb Arguments'.
Let's do 'Set Subject To Command Done' instead.

Initial WIP commit