Stop script injections from rendering in comments

[Cleop]

At the moment I can add a script to a comment on github and whilst it won't render on github, it will on our site.

• [x] Prevent scripts from running

[Cleop]

https://hex.pm/packages/html_sanitize_ex will apparently help to solve this!

[nelsonic]

@Cleop looks good. thanks for resolving. 👍