Examine source code of Gitcolor - Github Themer

{
  "name": "Gitcolor - Github Contribution Themer",
  "short_name": "Gitcolor",
  "version": "0.1.2",
  "description": "Set different themes to the GitHub contribution graph",
  "permissions": [
    "storage",
    "activeTab"
  ],
  "content_scripts": [
    {
      "matches": [
        "*://github.com/*"
      ],
      "js": [
        "content.js"
      ]
    }
  ],
  "web_accessible_resources": [
    "assets/theme.svg"
  ],
  "icons": {
    "24": "assets/favicon-24x24.png",
    "32": "assets/favicon-32x32.png"
  },
  "browser_action": {
    "browser_style": true,
    "default_popup": "popup.html"
  },
  "manifest_version": 2,
  "browser_specific_settings": {
    "gecko": {
      "id": "{79bbd2bd-713d-470c-9e0e-015dc5e531ac}"
    }
  }
}