Examine source code of Neutral Reddit Masstagger

{
  "manifest_version": 2,
  "name": "NRMT",
  "version": "3.4.1",
  "description": "old.reddit masstagger.",
  "homepage_url": "https://github.com/Mothrakk",
  "browser_action": {
    "default_icon": {
      "16": "popup/icon.png"
    },
    "default_title": "NRMT",
    "default_popup": "popup/popup.html"
  },
  "content_scripts": [
    {
      "matches": [
        "*://old.reddit.com/*"
      ],
      "js": [
        "main.js"
      ]
    }
  ],
  "permissions": [
    "storage"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{007e5327-f1ba-433d-aead-41cab2b7afb1}",
      "strict_min_version": "57.0a1"
    }
  }
}