Examine source code of Reddit Sidebar Toggle+

{
  "manifest_version": 2,
  "name": "Reddit Sidebar Toggle+",
  "version": "1.0",
  "homepage_url": "https://github.com/KazaKazan/reddit-sidebar-toggle",
  "description": "Toggle the sidebar on reddit.com, remembers the last state on page load.",
  "permissions": [
    "activeTab",
    "storage"
  ],
  "icons": {
    "48": "icons/reddit.svg",
    "96": "icons/reddit.svg"
  },
  "browser_action": {
    "default_icon": "icons/reddit.svg",
    "default_title": "Reddit: Toggle Sidebar"
  },
  "background": {
    "scripts": [
      "scripts/background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.reddit.com/*"
      ],
      "js": [
        "./scripts/reddit.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{a82c0a86-7c6d-482d-b0da-a198086f021d}"
    }
  }
}