fix(package): update markdown-it to version 8.3.1

https://greenkeeper.io/

Author: greenkeeper[bot]

package.json

@@ -10,7 +10,7 @@
   "dependencies": {
     "handlebars": "4.0.6",
     "highlight.js": "9.9.0",
-    "markdown-it": "8.3.0"
+    "markdown-it": "8.3.1"
   },
   "devDependencies": {
     "@neogeek/eslint-config-standards": "1.13.1",