fix(package): update ngx-markdown to version 8.2.2

Closes #84

Author: greenkeeper[bot]

demo/package.json

@@ -49,7 +49,7 @@
     "material-design-icons": "^3.0.1",
     "ngx-clipboard": "^11.1.9",
     "ngx-highlightjs": "2.1.1",
-    "ngx-markdown": "^7.1.4",
+    "ngx-markdown": "^8.2.2",
     "ngx-material-pages": "^1.3.2",
     "rxjs": "^6.4.0",
     "rxjs-compat": "^6.4.0",