【优化】采用 marked 重写 md 渲染，增加 code 复制功能

package.json

@@ -29,7 +29,6 @@
     "@form-create/designer": "^3.1.3",
     "@form-create/element-ui": "^3.1.24",
     "@iconify/iconify": "^3.1.1",
-    "@iktakahiro/markdown-it-katex": "^4.0.1",
     "@microsoft/fetch-event-source": "^2.0.1",
     "@videojs-player/vue": "^1.0.0",
     "@vueuse/core": "^10.9.0",
@@ -53,7 +52,7 @@
     "highlight.js": "^11.9.0",
     "jsencrypt": "^3.3.2",
     "lodash-es": "^4.17.21",
-    "markdown-it": "^14.1.0",
+    "marked": "^12.0.2",
     "min-dash": "^4.1.1",
     "mitt": "^3.0.1",
     "nprogress": "^0.2.0",