Update marked requirement from ^0.3.9 to ^0.5.2

Updates the requirements on [marked](https://github.com/markedjs/marked) to permit the latest version.
- [Release notes](https://github.com/markedjs/marked/releases)
- [Commits](https://github.com/markedjs/marked/commits/v0.5.2)

Signed-off-by: dependabot[bot] <support@dependabot.com>

package.json

@@ -26,7 +26,7 @@
   "license": "MIT",
   "dependencies": {
     "hexo-util": "^0.6.2",
-    "marked": "^0.3.9",
+    "marked": "^0.5.2",
     "object-assign": "^4.1.1",
     "strip-indent": "^2.0.0"
   },