SelectionSort: add missing Javadoc for class and findIndexOfMin method

src/main/java/com/thealgorithms/sorts/SelectionSort.java

@@ -1,5 +1,10 @@
 package com.thealgorithms.sorts;
 
+/**
+ * Implementation of the Selection Sort algorithm.
+ *
+ * @see SortAlgorithm
+ */
 public class SelectionSort implements SortAlgorithm {
     /**
      * Generic Selection Sort algorithm.
@@ -11,18 +16,27 @@ public class SelectionSort implements SortAlgorithm {
      *
      * Space Complexity: O(1) – in-place sorting.
      *
-     * @see SortAlgorithm
+     * @param array the array to be sorted
+     * @param <T> the type of elements in the array
+     * @return the sorted array
      */
     @Override
     public <T extends Comparable<T>> T[] sort(T[] array) {
-
         for (int i = 0; i < array.length - 1; i++) {
             final int minIndex = findIndexOfMin(array, i);
             SortUtils.swap(array, i, minIndex);
         }
         return array;
     }
 
+    /**
+     * Finds the index of the minimum element in the array starting from a given index.
+     *
+     * @param array the array to search
+     * @param startIndex the index to start searching from
+     * @param <T> the type of elements in the array
+     * @return the index of the minimum element
+     */
     private static <T extends Comparable<T>> int findIndexOfMin(T[] array, final int startIndex) {
         int minIndex = startIndex;
         for (int i = startIndex + 1; i < array.length; i++) {