Examine source code of HaxBall Sentiment

{
  "manifest_version": 2,
  "name": "HaxBall Sentiment",
  "version": "3.0",
  "version_name": "3.0 beta",
  "description": "Web Extension for online game Haxball",
  "homepage_url": "https://github.com/peppepol/Haxball_Sentiment",
  "icons": {
    "48": "icons/hb48.png",
    "96": "icons/hb96.png"
  },
  "permissions": [
    "activeTab",
    "storage",
    "tabs"
  ],
  "browser_action": {
    "default_icon": "icons/hb32.png",
    "default_title": "HaxBall Sentiment",
    "default_popup": "popup/popup.html"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.haxball.com/*"
      ],
      "js": [
        "dist/bundle.js"
      ]
    }
  ],
  "web_accessible_resources": [],
  "browser_specific_settings": {
    "gecko": {
      "id": "{07883f0b-59b0-4bba-ad68-c44a0ffe2594}"
    }
  }
}