Fix multilingual content typos (#1958)

en/codes/kotlin/chapter_searching/binary_search_insertion.kt

@@ -35,7 +35,7 @@ fun binarySearchInsertion(nums: IntArray, target: Int): Int {
         } else if (nums[m] > target) {
             j = m - 1 // target is in the interval [i, m-1]
         } else {
-            j = m - 1 // The first element less than target is in the interval [i, m-1]
+            j = m - 1 // The rightmost element less than target is in the interval [i, m-1]
         }
     }
     // Return insertion point i
@@ -62,4 +62,4 @@ fun main() {
         val index = binarySearchInsertion(nums, target)
         println("Insertion point index for element $target is $index")
     }
-}
+}