Examine source code of Fangraphs Navigator

{
  "manifest_version": 2,
  "name": "Fangraphs Navigator",
  "version": "1.1.0",
  "author": "Dan Grochmal",
  "description": "Navigate to a Fangraphs player page from the address bar or by right clicking",
  "omnibox": {
    "keyword": "fg"
  },
  "permissions": [
    "contextMenus"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "icons": {
    "16": "icon16.png",
    "32": "icon32.png",
    "48": "icon48.png",
    "128": "icon128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{e3f368e8-e65d-407b-8a0e-64786d85119d}"
    }
  }
}