Derives borrowed MMDB map decoding for a struct.
Fields such as &str and &[u8] borrow the source database bytes.
Unsupported or missing required fields produce a decoding error.
§Examples
ⓘuse libmaxminddb_rs::MmdbDecode;
#[derive(MmdbDecode)]
struct Record<'a> { country: &'a str, asn: u32 }