* Add security headers to nginx config
Increase the security of the nginx server and the served page, by adding the following security headers to the nginx config:
- X-Frame-Options (Disables click jacking by disallowing the page to be run in a frame/iframe)
- X-XSS-Protection (Enables cross site scripting filtering)
- X-Content-Type-Options (Disables MIME sniffing and forces browser to use the type given in Content-Type.)
- Content-Security-Policy (Controls resources the user agent is allowed to load for a given page.)
- Referrer-Policy (Governs which referrer information sent in the Referer header should be included with requests made.)
Additional headers that could be added optionally:
- Strict-Transport-Security (Enforce HTTPS over HTTP)
