GitHub go to line number

manifest.json

{
  "update_url": "https://clients2.google.com/service/update2/crx",
  "manifest_version": 2,
  "name": "GitHub go to line number",
  "description": "Open-source extension which adds a go to line number modal right into GitHub",
  "short_name": "Github goto",
  "version": "1.2.0",
  "icons": {
    "16": "icons/16.png",
    "19": "icons/19.png",
    "38": "icons/38.png",
    "48": "icons/48.png",
    "128": "icons/128.png"
  },
  "content_scripts": [
    {
      "matches": [
        "https://www.github.com/*",
        "http://www.github.com/*",
        "https://github.com/*",
        "http://github.com/*"
      ],
      "js": [
        "content.js"
      ],
      "run_at": "document_idle"
    }
  ],
  "permissions": [],
  "web_accessible_resources": [
    "modal.html"
  ]
}