Examine source code of Edit Button

{
  "name": "Edit Button",
  "description": "Show a button if the page you are viewing is editable.",
  "version": "1.0.7",
  "manifest_version": 3,
  "action": {
    "default_icon": "/assets/pen.png",
    "default_title": "Edit this page"
  },
  "page_action": {
    "default_icon": "/assets/pen.svg",
    "default_title": "Edit this page"
  },
  "permissions": [
    "tabs",
    "activeTab",
    "storage",
    "webNavigation",
    "scripting"
  ],
  "options_ui": {
    "page": "options.html",
    "open_in_tab": true
  },
  "background": {
    "service_worker": "background.js",
    "scripts": [
      "background.js"
    ],
    "type": "module"
  },
  "host_permissions": [
    "<all_urls>"
  ],
  "options_page": "options.html",
  "web_accessible_resources": [
    {
      "resources": [
        "cross_origin_dialog.html",
        "cross_origin_dialog.js"
      ],
      "matches": [
        "<all_urls>"
      ]
    }
  ],
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "polyfill.js"
      ],
      "run_at": "document_start"
    },
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "app.js"
      ]
    },
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "cross_origin_dialog.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "edit-button@edit-button"
    }
  },
  "commands": {
    "open-edit-link": {
      "suggested_key": {
        "default": "Ctrl+E",
        "mac": "Command+Shift+E"
      },
      "description": "Open edit link"
    }
  }
}