Examine source code of Warn Common Password

{
  "description": "Displays warning notification if word entered in any password field is present in 500000 common passwords. Works entirely offline.",
  "manifest_version": 2,
  "name": "Warn Common Password",
  "version": "0.0.11resigned1",
  "homepage_url": "https://github.com/gkrishnaks/",
  "icons": {
    "48": "icons/lockIcon.png"
  },
  "applications": {
    "gecko": {
      "id": "gokulakrishna.k.s@gmail.com",
      "strict_min_version": "57.0"
    }
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "permissions": [
    "notifications",
    "storage"
  ],
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ]
    }
  ]
}