Examine source code of Steam Context Menu

{
  "name": "Steam Context Menu",
  "description": "Search Steam using the context menu",
  "version": "1.2.3resigned1",
  "applications": {
    "gecko": {
      "id": "steam-context-menu@skylark95.com",
      "strict_min_version": "48.0"
    }
  },
  "permissions": [
    "contextMenus",
    "storage",
    "tabs"
  ],
  "icons": {
    "16": "icon-bitty.png",
    "48": "icon-small.png",
    "128": "icon-large.png"
  },
  "background": {
    "scripts": [
      "steamContextMenu.js"
    ]
  },
  "options_ui": {
    "page": "options.html"
  },
  "manifest_version": 2
}