remarkable as optionable

[Mte90]

If I don't care about the markdown support I get from the JS bundle in this project:

Uncaught ReferenceError: remarkable is not defined
    <anonymous> http://127.0.0.1:8000/static/django_comments_xtd/js/django-comments-xtd-2.9.13.js:1330

[danirus]

How do you propose to do it optional?

[Mte90]

I didn't still checked the JS code but I think that should be enough check if the remarkable object exists and in that case execute the code.