Examine source code of ModernDeck

{
  "name": "__MSG_name__",
  "short_name": "ModernDeck",
  "description": "__MSG_description__",
  "author": "dangered wolf",
  "version": "10.0",
  "default_locale": "en",
  "permissions": [
    "declarativeNetRequest"
  ],
  "host_permissions": [
    "https://tweetdeck.twitter.com/*"
  ],
  "declarative_net_request": {
    "rule_resources": [
      {
        "id": "moderndeck_dnr",
        "enabled": true,
        "path": "extension/dnr_rules.json"
      }
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "https://tweetdeck.twitter.com/*"
      ],
      "js": [
        "extension/content.js"
      ],
      "run_at": "document_end"
    }
  ],
  "icons": {
    "16": "ModernDeck16.png",
    "24": "ModernDeck24.png",
    "32": "ModernDeck32.png",
    "48": "ModernDeck48.png",
    "64": "ModernDeck64.png",
    "128": "ModernDeck128.png",
    "150": "ModernDeck150.png"
  },
  "web_accessible_resources": [
    {
      "resources": [
        "assets",
        "assets/*",
        "assets/css/*",
        "assets/js/*",
        "assets/fonts/*",
        "assets/libraries/*",
        "assets/img/*"
      ],
      "matches": [
        "https://tweetdeck.twitter.com/*"
      ]
    }
  ],
  "action": {
    "default_icon": "ModernDeck64.png",
    "default_popup": "extension/popover.html",
    "default_title": "__MSG_launch__"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{d161e212-26d7-4a57-8fb8-3eb69c5b1a0b}",
      "strict_min_version": "109.0"
    }
  },
  "manifest_version": 3
}