🔒️(nginx) manage Content-Security-Policy in nginx config

The media route is managed by nginx. On this route we want to add the
Content-Security-Header to forbid fetching any resources.
See : https://content-security-policy.com/

src/helm/impress/Chart.yaml

@@ -1,5 +1,5 @@
 apiVersion: v2
 type: application
 name: docs
-version: 2.2.0-beta.1
+version: 2.2.0-beta.2
 appVersion: latest