Remove pointless documentation

Author: hannesa2

MPChartLib/src/main/java/com/github/mikephil/charting/interfaces/dataprovider/ChartInterface.java

@@ -16,38 +16,28 @@ public interface ChartInterface {
 
     /**
      * Returns the minimum x value of the chart, regardless of zoom or translation.
-     *
-     * @return
      */
     float getXChartMin();
 
     /**
      * Returns the maximum x value of the chart, regardless of zoom or translation.
-     *
-     * @return
      */
     float getXChartMax();
 
     float getXRange();
 
     /**
      * Returns the minimum y value of the chart, regardless of zoom or translation.
-     *
-     * @return
      */
     float getYChartMin();
 
     /**
      * Returns the maximum y value of the chart, regardless of zoom or translation.
-     *
-     * @return
      */
     float getYChartMax();
 
     /**
      * Returns the maximum distance in scren dp a touch can be away from an entry to cause it to get highlighted.
-     *
-     * @return
      */
     float getMaxHighlightDistance();