feat: adds leetcode 2942 answer

provided I've already submitted on leetcode, I brought it over to vscode now

Author: AmiyahJo

lesson_11/arrays_java/arrays_app/src/main/java/com/codedifferently/lesson11/Lesson11.java

@@ -1,5 +1,6 @@
 package com.codedifferently.lesson11;
 
+import java.util.ArrayList;
 import java.util.List;
 
 public class Lesson11 {
@@ -26,6 +27,13 @@ public int[] getConcatenation(int[] nums) {
    * https://leetcode.com/problems/find-words-containing-character/
    */
   public List<Integer> findWordsContaining(String[] words, char x) {
-    return null;
+    List<Integer> indices = new ArrayList<>();
+
+        for (int i = 0; i < words.length; i++){
+            if(words[i].indexOf(x) >= 0){
+                indices.add(i);
+            }
+        }
+        return indices;
   }
 }