Examine source code of QuantumVim

{
  "manifest_version": 2,
  "name": "QuantumVim",
  "version": "1.4resigned1",
  "author": "Shing Lyu & Johnathan Hao",
  "description": "Adds basic vim commands to Firefox 48+ (with e10s & WebExtension)",
  "icons": {
    "48": "icons/icon-48.png"
  },
  "permissions": [
    "tabs",
    "sessions"
  ],
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "vim.js",
        "focusin.min.js"
      ],
      "run_at": "document_start",
      "match_about_blank": true
    }
  ],
  "background": {
    "scripts": [
      "vim-background.js"
    ],
    "persistent": false
  },
  "commands": {
    "close_system_tabs": {
      "suggested_key": {
        "default": "Ctrl+Z",
        "mac": "Command+Z",
        "linux": "Ctrl+Z"
      },
      "description": "Close system tabs that doesn't work with QuantumVim"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{97402c5d-bfd9-4847-be01-dbd4685a5cd6}"
    }
  }
}