Examine source code of Trigger Warning

{
  "manifest_version": 3,
  "version": "2.0",
  "name": "Trigger Warning",
  "description": "Plugin for flagging possibly harmful language",
  "browser_specific_settings": {
    "gecko": {
      "id": "triggerwarning@gmail.com"
    }
  },
  "icons": {
    "16": "src/images/Trigger_Warning16.png",
    "32": "src/images/Trigger_Warning32.png",
    "48": "src/images/Trigger_Warning48.png",
    "128": "src/images/Trigger_Warning128.png"
  },
  "action": {
    "default_title": "Trigger Warning"
  },
  "content_scripts": [
    {
      "matches": [
        "https://twitter.com/compose/tweet/*",
        "https://www.facebook.com/*",
        "https://www.tumblr.com/new/text*",
        "https://www.reddit.com/submit*"
      ],
      "js": [
        "script.min.js"
      ]
    }
  ]
}