fixed some JavaDoc mistakes

GameProject/src/base/GameLoop.java

@@ -217,8 +217,8 @@ public class GameLoop {
 
 
   /**
-   * main to start the whole application.
-   * initializes the {@link #levels} ArrayList of Playground instances (levels) to be played with one level {@link SpaceInvadersLevel} in constructor of {@link #GameLoop}.
+   * main to start the whole application. It calls. {@link #runGame(String[])}.
+   * (levels are automatically added/loaded by constructor of {@link #GameLoop}).
    * 
    * @param args Java default command line args, forwarded to {@link #runGame(String[])}
    * @throws IOException in case highscore.txt cannot be written.

GameProject/src/playground/Level2.java

@@ -3,7 +3,7 @@ package playground;
 
 
 /**
- * extends extends {@link SpaceInvadersLevel} with a different startup message.
+ * extends {@link SpaceInvadersLevel} with a different startup message.
  */
 public class Level2 extends SpaceInvadersLevel {
 

GameProject/src/playground/Level4.java

@@ -10,7 +10,7 @@ import org.apache.logging.log4j.Logger;
 
 
 /**
- * extends extends {@link SpaceInvadersLevel}
+ * extends {@link SpaceInvadersLevel}
  * <ul>
  * <li>Hit aliens twice to kill them
  * <li>they say AUA when not destroyed