chore: add documentation for packets say, in player, cinfo

Merge pull request #12 from Rutherther/packets

Implement custom packet serializer

feat: add client SayPacket

feat: enable inline converters in all packets

feat: add packets (ncif, u_as, pusle, msg, say, st, stat, c_mode, lev, ski, sr)

fix: fix attribute indexes in walk packet

feat: add walk packet