docs(filetypes): add comments for bzip variants

Signed-off-by: Christina Sørensen <christina@cafkafk.com>

src/info/filetype.rs

@@ -214,9 +214,9 @@ const EXTENSION_TYPES: Map<&'static str, FileType> = phf_map! {
     "ar"         => FileType::Compressed,
     "arj"        => FileType::Compressed,
     "br"         => FileType::Compressed, // Brotli
-    "bz"         => FileType::Compressed,
+    "bz"         => FileType::Compressed, // bzip
     "bz2"        => FileType::Compressed, // bzip2
-    "bz3"        => FileType::Compressed,
+    "bz3"        => FileType::Compressed, // bzip3
     "cpio"       => FileType::Compressed,
     "deb"        => FileType::Compressed, // Debian
     "dmg"        => FileType::Compressed,