Assert a std::fs::read_to_string(path) value is less than or equal to another.
Pseudocode:
std::fs::read_to_string(path1) ≤ std::fs::read_to_string(path2)
§Example
use assertables::*;
let a ="alfa.txt";
let b ="bravo.txt";
assert_fs_read_to_string_le!(&a, &b);
§Module macros