docs: add Japanese translate documents (#1812)

* docs: add Japanese documents (`ja/docs`)

* docs: add Japanese documents (`ja/codes`)

* docs: add Japanese documents

* Remove pythontutor blocks in ja/

* Add an empty at the end of each markdown file.

* Add the missing figures (use the English version temporarily).

* Add index.md for Japanese version.

* Add index.html for Japanese version.

* Add missing index.assets

* Fix backtracking_algorithm.md for Japanese version.

* Add avatar_eltociear.jpg. Fix image links on the Japanese landing page.

* Add the Japanese banner.

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Co-authored-by: krahets <krahets@163.com>

ja/codes/python/chapter_tree/binary_tree.py

@@ -0,0 +1,41 @@
+"""
+File: binary_tree.py
+Created Time: 2022-12-20
+Author: a16su (lpluls001@gmail.com)
+"""
+
+import sys
+from pathlib import Path
+
+sys.path.append(str(Path(__file__).parent.parent))
+from modules import TreeNode, print_tree
+
+
+"""ドライバコード"""
+if __name__ == "__main__":
+    # 二分木を初期化
+    # ノードを初期化
+    n1 = TreeNode(val=1)
+    n2 = TreeNode(val=2)
+    n3 = TreeNode(val=3)
+    n4 = TreeNode(val=4)
+    n5 = TreeNode(val=5)
+    # ノードの参照（ポインタ）を構築
+    n1.left = n2
+    n1.right = n3
+    n2.left = n4
+    n2.right = n5
+    print("\n二分木を初期化\n")
+    print_tree(n1)
+
+    # ノードの挿入と削除
+    P = TreeNode(0)
+    # ノードPを n1 -> n2 の間に挿入
+    n1.left = P
+    P.left = n2
+    print("\nノードPを挿入後\n")
+    print_tree(n1)
+    # ノードを削除
+    n1.left = n2
+    print("\nノードPを削除後\n")
+    print_tree(n1)