Examine source code of All PR Files Viewed

{
  "manifest_version": 2,
  "name": "All PR Files Viewed",
  "description": "Set all files in a PR viewed (Github / Gitlab)",
  "author": "Iván Córdoba Donet",
  "version": "0.1.0",
  "icons": {
    "16": "assets/icon_16.png",
    "32": "assets/icon_32.png",
    "48": "assets/icon_48.png",
    "64": "assets/icon_64.png",
    "128": "assets/icon_128.png"
  },
  "permissions": [
    "activeTab"
  ],
  "background": {
    "scripts": [
      "js/background.js"
    ]
  },
  "browser_action": {
    "default_title": "All PR Files Viewed"
  },
  "content_scripts": [
    {
      "matches": [
        "https://github.com/*",
        "https://gitlab.com/*"
      ],
      "js": [
        "js/messenger.js"
      ]
    }
  ]
}