TODO: Handle Anonymous functions correctly

[CFiggers]

Currently will re-format Janet's anonymous function macro, which should look like this:

|(fn args)

to this instead:

| (fn args

Fortunately doesn't cause anonymous function to break (Janet ignores the whitespace) but should still fix.

Probably as simple as adding | to a regex somewhere that handles prefixes (like # or @ in other places).

[CFiggers]

Partially fixed—now having a | in a form makes format-on-type behave weirdly.

[CFiggers]

Fixed with b7111abef43f71d2de832e72d710213fdf7923c6