feat: implement markdown file preview in Ace editor (#3431)

---------

Co-authored-by: Oleg Lobanov <oleg@lobanov.me>

frontend/package-lock.json

@@ -18,6 +18,7 @@
         "js-base64": "^3.7.7",
         "jwt-decode": "^4.0.0",
         "lodash-es": "^4.17.21",
+        "marked": "^14.1.0",
         "material-icons": "^1.13.12",
         "normalize.css": "^8.0.1",
         "pinia": "^2.1.7",
@@ -5810,6 +5811,18 @@
         "node": ">=12"
       }
     },
+    "node_modules/marked": {
+      "version": "14.1.0",
+      "resolved": "https://registry.npmmirror.com/marked/-/marked-14.1.0.tgz",
+      "integrity": "sha512-P93GikH/Pde0hM5TAXEd8I4JAYi8IB03n8qzW8Bh1BIEFpEyBoYxi/XWZA53LSpTeLBiMQOoSMj0u5E/tiVYTA==",
+      "license": "MIT",
+      "bin": {
+        "marked": "bin/marked.js"
+      },
+      "engines": {
+        "node": ">= 18"
+      }
+    },
     "node_modules/marks-pane": {
       "version": "1.0.9",
       "resolved": "https://registry.npmjs.org/marks-pane/-/marks-pane-1.0.9.tgz",