v0.2

Changes:

• Refine speed levels.
  Now the game has 8 fixed speed levels, and the max speed is not as crazy as before.
  Also, the speed level is now shown on the interface.

• Update score counting.
  Now players are finally rewarded for clearing multiple rows at once, so their score is multiplied by the number of cleared rows!
  Basically, players now get 4 points for clearing 2 rows at once, 9 points for 3 rows, and 16 points for 4 rows at once (a.k.a "Tetris")!

• Render the grid with smaller boxes so it fits better on smaller screens when playing in the browser.

Features to be added in future releases:

• Proper main menu and "Game Over" screens
• Leaderboard