Misprint in readme:showLeaderboard

[rotoxl]

In readme, section "Show specific leaderboard" theres a misprint:

Should be:

var data = {
    leaderboardId: "board1"
};
googleplaygame.showLeaderboard(data);

(says googleplaygame.showLeaderboard(leaderboardId);)

[Samleo8]

Yes, this desperately needs to be changed.. Caused me much problems.
README also needs to be edited for the cordova-plugin-play-game-services plugin by @artberri which forks this one.