feat: add mindmap (#419)

Author: antonreshetov

package.json

@@ -50,6 +50,7 @@
     "codemirror": "^5.65.7",
     "codemirror-textmate": "^1.1.0",
     "crypto-js": "^4.1.1",
+    "d3": "^7.8.5",
     "date-fns": "^2.28.0",
     "dom-to-image": "^2.6.0",
     "electron-store": "^8.0.1",
@@ -62,6 +63,9 @@
     "lodash": "^4.17.21",
     "lowdb": "^3.0.0",
     "marked": "^4.0.17",
+    "markmap-common": "^0.15.3",
+    "markmap-lib": "^0.15.4",
+    "markmap-view": "^0.15.4",
     "mermaid": "^9.1.3",
     "mitt": "^3.0.0",
     "nanoid": "^3.3.1",