Operators/functions documentation

[sylque]

Unless I'm misunderstanding something, the Grammar chapter is outdated compared to the TinyExpr Changes page, with many missing operators.

It's not a big issue but it's a shame, because this Grammar chapter was what popped out for me when I first went through your main page.

Side note: there's no LOGICAL NOT operator, right? I don't need it right now, but I couldn't help but noticing this absence :-)

[Blake-Madden]

There is the NOT function, but no operator. I had thought of adding a ! operator for logical not, but was concerned that users would expect for ! to be meant for factorials (e.g., 5!) instead. So I decided to not support ! for either situation and just rely on the functions NOT and FAC for those purposes.

[sylque]

It makes sense, thanks.