Examine source code of GitHub-Jira Link

{
  "manifest_version": 2,
  "description": "Adds links to Jira tickets on GitHub pull request pages",
  "name": "GitHub-Jira Link",
  "version": "0.2.0",
  "icons": {
    "128": "icon_128.png"
  },
  "content_scripts": [
    {
      "matches": [
        "https://github.com/*",
        "https://www.github.com/*"
      ],
      "css": [
        "styles.css"
      ],
      "js": [
        "contentScript.js"
      ],
      "run_at": "document_idle"
    }
  ],
  "permissions": [
    "activeTab",
    "storage"
  ],
  "options_ui": {
    "page": "options.html",
    "open_in_tab": false
  },
  "applications": {
    "gecko": {
      "id": "github-jira@link"
    }
  },
  "browser_action": {
    "browser_style": true,
    "default_popup": "options.html",
    "default_icon": {
      "16": "icon_16.png",
      "32": "icon_32.png"
    }
  }
}