Examine source code of cs-academy-vim

{
  "description": "Activates vim mode in the CS academy editor >:)",
  "manifest_version": 2,
  "name": "cs-academy-vim",
  "version": "1.0",
  "author": "bowad",
  "homepage_url": "https://github.com/jurplel/cs-academy-vim",
  "icons": {
    "48": "icons/vim.png"
  },
  "web_accessible_resources": [
    "mobilize.js"
  ],
  "content_scripts": [
    {
      "matches": [
        "*://*.cs.cmu.edu/*"
      ],
      "js": [
        "inject.js"
      ]
    }
  ],
  "permissions": [
    "activeTab",
    "*://*.cs.cmu.edu/*"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{19cef13b-8fc8-4e73-8ff7-fcefe5adaae0}"
    }
  }
}