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.

---------

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

ja/codes/python/modules/print_util.py

@@ -0,0 +1,81 @@
+"""
+File: print_util.py
+Created Time: 2021-12-11
+Author: krahets (krahets@163.com), msk397 (machangxinq@gmail.com)
+"""
+
+from .tree_node import TreeNode, list_to_tree
+from .list_node import ListNode, linked_list_to_list
+
+
+def print_matrix(mat: list[list[int]]):
+    """行列を出力"""
+    s = []
+    for arr in mat:
+        s.append("  " + str(arr))
+    print("[\n" + ",\n".join(s) + "\n]")
+
+
+def print_linked_list(head: ListNode | None):
+    """連結リストを出力"""
+    arr: list[int] = linked_list_to_list(head)
+    print(" -> ".join([str(a) for a in arr]))
+
+
+class Trunk:
+    def __init__(self, prev, string: str | None = None):
+        self.prev = prev
+        self.str = string
+
+
+def show_trunks(p: Trunk | None):
+    if p is None:
+        return
+    show_trunks(p.prev)
+    print(p.str, end="")
+
+
+def print_tree(
+    root: TreeNode | None, prev: Trunk | None = None, is_right: bool = False
+):
+    """
+    二分木を出力
+    この木プリンタはTECHIE DELIGHTから借用
+    https://www.techiedelight.com/c-program-print-binary-tree/
+    """
+    if root is None:
+        return
+
+    prev_str = "    "
+    trunk = Trunk(prev, prev_str)
+    print_tree(root.right, trunk, True)
+
+    if prev is None:
+        trunk.str = "———"
+    elif is_right:
+        trunk.str = "/———"
+        prev_str = "   |"
+    else:
+        trunk.str = "\———"
+        prev.str = prev_str
+
+    show_trunks(trunk)
+    print(" " + str(root.val))
+    if prev:
+        prev.str = prev_str
+    trunk.str = "   |"
+    print_tree(root.left, trunk, False)
+
+
+def print_dict(hmap: dict):
+    """辞書を出力"""
+    for key, value in hmap.items():
+        print(key, "->", value)
+
+
+def print_heap(heap: list[int]):
+    """ヒープを出力"""
+    print("ヒープの配列表現:", heap)
+    print("ヒープの木表現:")
+    root: TreeNode | None = list_to_tree(heap)
+    print_tree(root)