Examine source code of GifHub

{
  "manifest_version": 2,
  "name": "GifHub",
  "short_name": "GifHub",
  "description": "Adds support for gifv/webm/mp4 to discussions on github.com",
  "version": "1.0.14resigned1",
  "browser_action": {
    "default_title": "Adds support for gifv/webm/mp4 to discussions on github.com",
    "default_icon": "icon.png"
  },
  "icons": {
    "128": "icon.png"
  },
  "permissions": [
    "activeTab",
    "webRequest",
    "webRequestBlocking",
    "https://github.com/*"
  ],
  "background": {
    "scripts": [
      "vendor/lodash.js",
      "supported_hosts.js",
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "https://github.com/*"
      ],
      "js": [
        "vendor/lodash.js",
        "supported_hosts.js",
        "gifhub.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{799a3553-3cb1-4289-913b-11eb7da466d9}"
    }
  }
}