v0.4.0

What's Changed

• Add diagnostic notation serializer by @nitely in #28
• Add CDDL parser by @nitely in #29
• CDDL: any -> CborBytes; tools/cddl -> cddl by @nitely in #30
• Perf improvement by @nitely in #17
• CDDL: int -> int64; uint -> uint64 by @nitely in #31
• Bump to v0.4.0 by @nitely in #32

Full Changelog: v0.3.0...v0.4.0