Possible index out of bounds in comment parsing code

[Mingun]

Code here will panic on input .<!-:

maybe_xml/maybe_xml/src/read/scanner.rs

Lines 117 to 121 in 1005d17

	let peek4 = pos + 3;
	if input.len() < peek4 {
	return None;
	}
	match input[peek4] {

index out of bounds: the len is 4 but the index is 4

Need to use <= as in all similar places. I don't do PR because I'm not sure what your test policy is, and currently I don't have time to write them.

[Mingun]

Also it is probably better to change == to <= in tokenize and parse methods to avoid possible panics:

maybe_xml/maybe_xml/src/read.rs

Lines 161 to 165 in 1005d17

	if input.len() == *pos {
	return None;
	}
	assert!(crate::is_utf8_boundary(input[*pos]));

maybe_xml/maybe_xml/src/read.rs

Lines 230 to 237 in 1005d17

	if input.len() == pos {
	return None;
	}
	assert!(
	crate::is_utf8_boundary(input[pos]),
	"pos is not at a character boundary"
	);