i18 support for markdown editor tooltip

packages/node_modules/@node-red/editor-client/locales/ja/editor.json

@@ -715,7 +715,19 @@
         "format": "JSONフォーマット"
     },
     "markdownEditor": {
-        "title": "マークダウンエディタ"
+        "title": "マークダウンエディタ",
+        "heading1": "見出しレベル1",
+        "heading2": "見出しレベル2",
+        "heading3": "見出しレベル3",
+        "bold": "太字",
+        "italic": "斜体",
+        "code": "コード",
+        "ordered-list": "箇条書き(番号付き)",
+        "unordered-list": "箇条書き",
+        "quote": "引用",
+        "link": "リンク",
+        "horizontal-rule": "区切り線",
+        "toggle-preview": "プレビュー表示切替え"
     },
     "bufferEditor": {
         "title": "バッファエディタ",