Update directory

Author: Hardvan

DIRECTORY.md

@@ -10,6 +10,7 @@
             * [AllPathsFromSourceToTarget](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/backtracking/AllPathsFromSourceToTarget.java)
             * [ArrayCombination](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/backtracking/ArrayCombination.java)
             * [Combination](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/backtracking/Combination.java)
+            * [CrosswordSolver](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/backtracking/CrosswordSolver.java)
             * [FloodFill](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/backtracking/FloodFill.java)
             * [KnightsTour](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/backtracking/KnightsTour.java)
             * [MazeRecursion](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/backtracking/MazeRecursion.java)
@@ -595,6 +596,7 @@
             * [AllPathsFromSourceToTargetTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/backtracking/AllPathsFromSourceToTargetTest.java)
             * [ArrayCombinationTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/backtracking/ArrayCombinationTest.java)
             * [CombinationTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/backtracking/CombinationTest.java)
+            * [CrosswordSolverTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/backtracking/CrosswordSolverTest.java)
             * [FloodFillTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/backtracking/FloodFillTest.java)
             * [MazeRecursionTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/backtracking/MazeRecursionTest.java)
             * [MColoringTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/backtracking/MColoringTest.java)