Examine source code of BlockedStack

{
  "manifest_version": 2,
  "name": "BlockedStack",
  "description": "Tools to improve your Substack experience",
  "version": "1.3.0",
  "icons": {
    "16": "icon/16.png",
    "28": "icon/28.png",
    "32": "icon/32.png",
    "48": "icon/48.png",
    "128": "icon/128.png"
  },
  "homepage_url": "https://chemicalmind.substack.com/p/tools",
  "permissions": [
    "storage",
    "activeTab",
    "scripting",
    "downloads",
    "notifications",
    "http://substack.com/*",
    "https://substack.com/*",
    "https://*.substack.com/*"
  ],
  "web_accessible_resources": [
    "main-world.js",
    "content-scripts/editor.css",
    "content-scripts/substack.css"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_title": "BlockedStack",
    "default_popup": "popup.html"
  },
  "content_scripts": [
    {
      "matches": [
        "https://*.substack.com/*"
      ],
      "js": [
        "content-scripts/editor.js"
      ]
    },
    {
      "matches": [
        "https://*.substack.com/*",
        "https://substack.com/*"
      ],
      "js": [
        "content-scripts/substack.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{63689d88-5381-42ea-82a8-08a49fb4b57e}"
    }
  }
}