Talk more about parsing

[tokenrove]

Lexing into words, and the strange interrelationship with parsing, especially once quoting is introduced, is really hard, and we don't talk about it at all here. It will be easier to expand this when I make pedagoguish, frosh, and squish public, each of which uses a different parsing strategy.

[tokenrove]

Link to some of these articles, too: http://www.oilshell.org/blog/tags.html?tag=parsing-shell#parsing-shell