Add Commands.runIf(...) as command factory method to Commands

wpilibNewCommands/src/main/java/edu/wpi/first/wpilibj2/command/Commands.java

@@ -166,6 +166,18 @@ public static Command either(Command onTrue, Command onFalse, BooleanSupplier se
     return new ConditionalCommand(onTrue, onFalse, selector);
   }
 
+  /**
+   * Runs a command if the boolean selector function is true.
+   *
+   * @param selector the selector function
+   * @param onTrue the command to run if the selector function returns true
+   * @return the command
+   * @see ConditionalCommand
+   */
+  public static Command runIf(BooleanSupplier selector, Command onTrue){
+    return onTrue.onlyIf(selector);
+  }
+
   /**
    * Runs one of several commands, based on the selector function.
    *