chore(package): updated dependencies

Author: AnthonyNahas

demo/package-lock.json

@@ -38,6 +38,7 @@
     "ngx-clipboard": "11.1.1",
     "ngx-disqus": "^2.3.7",
     "ngx-highlightjs": "^2.1.1",
+    "ngx-markdown": "^6.1.0",
     "ngx-material-pages": "^1.3.2",
     "rxjs": "^6.2.2",
     "rxjs-compat": "^6.2.2",