add strapi::security middleware docs on README

README.md

@@ -74,6 +74,42 @@ module.exports = ({ env }) => ({
 });
 ```
 
+- you may need also to add to the unlayer domain to the _Content Security Policy_. Update the config file `config/middleware.js` as:
+
+```diff
+// ...
+- "strapi::security",
++ {
++ name: "strapi::security",
++ config: {
++ contentSecurityPolicy: {
++ directives: {
++ "script-src": [
++ "'self'",
++ "'unsafe-inline'",
++ "editor.unlayer.com"
++ ],
++ "frame-src": [
++ "'self'",
++ "'unsafe-
++ inline'",
++ "editor.unlayer.com"
++ ],
++ "img-src": [
++ "'self'",
++ "data:",
++ "cdn.jsdelivr.net",
++ "strapi.io",
++ "s3.amazonaws.com",
++ `${env("AWS_BUCKET")}.s3.${env("AWS_REGION")}.amazonaws.com`
++ ],
++ },
++ },
++ },
++ },
+// ...
+```
+
 - After successful installation you've to build a fresh package that includes plugin UI. To archive that simply use:
 
 ```bash