Requires more detail documents on github Wiki #49

This issue is pointed in #40 by @roblabla and @MikKoz. Thanks for their report :-)
The point to fix is as follows(quoted from #40):

Wiki:

• description of various annotations,
• examples (with diagrams if possible) how pack/unpack of MessagePack works in Java.
• description about Value type.

NOTE: http://wiki.msgpack.org is removed because of resource problem, so we need to migrate wiki into github Wiki.