Several bug fixes and improvements (#945)

* Update Dockerfile for code debugging.

* Format Python code using Black.

* Improve dark theme by defining html classes for the figures, animations and cover images.

* Fix several glossary translation.

* Update a code comment.

* Fix climbing_stairs_backtrack: the pruning should not require the sorted choices list.

* Update the code of array and list traversal.

* Fix a rendering issue of README.md

* Update code of list traversal.

* Fix array_definition.png

* Update README.md

* Fix max_capacity_moving_short_board.png

* Fix array.dart

* Fix array.dart

* Fix array.dart

* Fix array.dart

codes/java/chapter_dynamic_programming/climbing_stairs_backtrack.java

@@ -18,7 +18,7 @@ public class climbing_stairs_backtrack {
         for (Integer choice : choices) {
             // 剪枝：不允许越过第 n 阶
             if (state + choice > n)
-                break;
+                continue;
             // 尝试：做出选择，更新状态
             backtrack(choices, state + choice, n, res);
             // 回退