fix(deps): update dependency markdown-it to v15

Author: renovate[bot]

package.json

@@ -84,7 +84,7 @@
     "katex": "^0.16.47",
     "lib0": "^0.2.117",
     "lowlight": "^3.3.0",
-    "markdown-it": "^14.3.0",
+    "markdown-it": "^15.0.0",
     "markdown-it-container": "^4.0.0",
     "markdown-it-footnote": "^4.0.0",
     "markdown-it-front-matter": "^0.2.4",