We skip the lint if the `loop {}` is in the `#[panic_handler]` as the
main recommendation we give is to panic, which obviously isn't
possible in a panic handler.
Signed-off-by: Joe Richey <joerichey@google.com>
We also update the documentation to note that the remediations are
different for `std` and `no_std` crates.
Signed-off-by: Joe Richey <joerichey@google.com>