Examine source code of Tumblr Savior

{
  "name": "Tumblr Savior",
  "version": "2.7.0",
  "description": "Would you like to control what shows up on your dashboard? Tumblr Savior is here to save you!",
  "action": {
    "default_icon": "data/Icon-16.png",
    "default_popup": "data/options.html",
    "default_title": "Tumblr Savior"
  },
  "background": {
    "scripts": [
      "data/main.js"
    ],
    "service_worker": "data/main.js"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "jid1-W5guVoyeUR0uBg@jetpack"
    }
  },
  "content_scripts": [
    {
      "exclude_globs": [
        "https://www.tumblr.com/upload/*"
      ],
      "js": [
        "data/script.js"
      ],
      "matches": [
        "https://www.tumblr.com/*"
      ],
      "run_at": "document_start"
    }
  ],
  "host_permissions": [
    "https://www.tumblr.com/*"
  ],
  "icons": {
    "16": "data/Icon-16.png",
    "32": "data/Icon-32.png",
    "48": "data/Icon-48.png",
    "64": "data/Icon-64.png",
    "128": "data/Icon-128.png"
  },
  "manifest_version": 3,
  "options_page": "data/options.html",
  "permissions": [
    "contextMenus",
    "storage"
  ]
}