add Lua/Luajit version
s/luajit/LuaJIT/g s/lua/Lua/g
add "The Guide to install Lua/LuaJIT for Mac OSX with brew."
Merge pull request #20 from y-ken/lua

高速スクリプト言語「Lua」版の追加リクエスト（LuaJIT対応）