fix rule typo in strings.xml

    <string name="next_block">Next Block</string>

    <string name="score">Score</string>

    <string name="rules">Combine the fast-paced falling block mechanics of Tetris with the number-merging gameplay of 2048. Merge blocks, create bigger numbers, and score high！

        \nSET - game setting\nBEST - top scores in the game\nStart Game - press to enter the game\n▶ - move the falling block right\n◀ - move the falling block right\n | | - pause the game\n ↻ - rotate the falling block by 90 degree </string>

        \nSET - game setting\nBEST - top scores in the game\nStart Game - press to enter the game\n▶ - move the falling block right\n◀ - move the falling block left\n | | - pause the game\n ↻ - rotate the falling block by 90 degree </string>

    <string name="highestscores">999\n998\n997\n996\n995\n</string><!--replace 99x with highest score data-->

</resources>