update protocol packet definitions: replace value receivers with pointer receivers in PacketID methods, expand FixedBitSet size from 8 to 256 bits, and remove outdated documentation files

pkg/protocol/packet/game/server/move_player_pos.go

@@ -8,7 +8,7 @@ type MovePlayerPos struct {
 	Flags       int8
 }
 
-func (MovePlayerPos) PacketID() packetid.ServerboundPacketID {
+func (*MovePlayerPos) PacketID() packetid.ServerboundPacketID {
 	return packetid.ServerboundMovePlayerPos
 }