Examine source code of Dev Redirector

{
  "manifest_version": 2,
  "name": "Dev Redirector",
  "version": "0.1",
  "description": "Redirect certain requests to custom URL",
  "permissions": [
    "<all_urls>",
    "storage",
    "webRequest",
    "webRequestBlocking"
  ],
  "icons": {
    "48": "icons/icon-48.png",
    "96": "icons/icon-96.png"
  },
  "browser_action": {
    "default_title": "Dev Redirector",
    "default_popup": "public/index.html"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{8f782482-35ef-48c2-b98e-1b009b5bcd9f}"
    }
  }
}