Macro text_block_fnl

macro_rules! text_block_fnl {
    ($($line:literal)*) => { ... };
}

Create a multiline string literal with a trailing newline.

Example:

let text = text_block_fnl! {
    "abc"
    "def"
    "ghi"
};
assert_eq!(text, "abc\ndef\nghi\n");