feat: Disable the auto detection of resource type

Protect yourself from malicious exploitation via MIME sniffing.
MIME-Type sniffing explained

Internet Explorer and Chrome browsers have a feature called "MIME-Type sniffing" that automatically detects a web resource's type. This means, for example, that a resource identified as an image can be read as a script if its content is a script.

This property allows a malicious person to send a file to your website to inject malicious code. We advise you to disable the MIME-Type sniffing to limit such activity.

Chrome has been working on a feature called Site Isolation which provides extensive mitigation against exploitation of these types of vulnerabilities. Site Isolation is more effective when MIME types are correct.
How to prevent MIME-Type sniffing

Configure a "X-Content-Type-Options" HTTP header. Add the "X-Content-Type-Options" HTTP header in the responses of each resource, associated to the "nosniff" value. It allows you to guard against such misinterpretations of your resources.

https://www.justegeek.fr/proteger-un-peu-plus-son-site-avec-la-balise-x-content-type-options/

nginx-default.conf

@@ -25,6 +25,9 @@ server {
 
     add_header X-UA-Compatible "IE=Edge,chrome=1";
 
+    # https://www.justegeek.fr/proteger-un-peu-plus-son-site-avec-la-balise-x-content-type-options/
+    add_header X-Content-Type-Options "nosniff";
+
     #Caching (save html pages for 7 days, rest as long as possible, no caching on frontpage)
     expires $expires;