README.md is now more readable.
README.md is now more readable.

SteamShon/incubator-s2graph,jongwook/incubator-s2graph,SteamShon/incubator-s2graph,jongwook/incubator-s2graph,SteamShon/incubator-s2graph,daewon/incubator-s2graph,daewon/incubator-s2graph