Examine source code of pepiStreamers

{
  "version": "1.0.0",
  "manifest_version": 2,
  "name": "pepiStreamers",
  "short_name": "Reste notifié des pépites qui sont en live !",
  "description": "Reste notifié des pépites qui sont en live !",
  "icons": {
    "128": "assets/images/logo.png"
  },
  "web_accessible_resources": [
    "assets/**"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "firefox@pepistreams.eu",
      "strict_min_version": "48.0"
    }
  },
  "browser_action": {
    "default_popup": "assets/html/popup.html"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "permissions": [
    "storage",
    "alarms",
    "notifications",
    "https://pepistreams.eu/"
  ],
  "content_security_policy": "script-src 'self'; font-src 'self' data: https://fonts.gstatic.com/s/dmsans; object-src 'self';"
}