Doesn't detect .pam files

[CheerfulPianissimo]

Here are a few sample files: https://filesamples.com/formats/pam

The file utility gives "Netpbm PAM image file, size = 640 x 426" and xdg-mime give "image/x-portable-arbitrarymap" but tree_magic_mini gives "application/octet-stream".

Sample code used:

let input: &[u8] = include_bytes!("../sample.pam");
dbg!(tree_magic_mini::from_u8(input));

Found in the context of waycrate/wayshot#107