**format_hex** formats an [u8] to an hexadecimal multiline format, for human readability.
```rust
let (l1, l2, l3) = FormatHex::new()
.push_hex(b"ABC")
.push_comment(" deb[")
.push_hex(b"DEFGHIJ")
.push_comment("]fin ")
.push_hex(b"KLMNzZ?\n\r\0")
.output();
assert_eq!(l1, "ABC deb[DEFGHIJ]fin KLMNzZ?↳←�");
assert_eq!(l2, "444.....4444444.....4444753000");
assert_eq!(l3, "123.....456789A.....BCDEAAFAD0");
```
License: MIT