Examine source code of Margin

{
  "manifest_version": 3,
  "name": "Margin",
  "description": "Annotate and highlight any webpage, with your notes saved to the decentralized AT Protocol.",
  "version": "0.3.13",
  "icons": {
    "16": "/icons/icon-16.png",
    "32": "/icons/icon-32.png",
    "48": "/icons/icon-48.png",
    "128": "/icons/icon-128.png"
  },
  "permissions": [
    "storage",
    "activeTab",
    "tabs",
    "cookies",
    "contextMenus"
  ],
  "host_permissions": [
    "https://margin.at/*",
    "*://*/*"
  ],
  "web_accessible_resources": [
    {
      "resources": [
        "pdfjs/*"
      ],
      "matches": [
        "<all_urls>"
      ]
    }
  ],
  "commands": {
    "toggle-sidebar": {
      "suggested_key": {
        "default": "Alt+M",
        "mac": "Alt+M"
      },
      "description": "Toggle Margin sidebar"
    },
    "annotate-selection": {
      "suggested_key": {
        "default": "Alt+A",
        "mac": "Alt+A"
      },
      "description": "Annotate selected text"
    },
    "highlight-selection": {
      "suggested_key": {
        "default": "Alt+H",
        "mac": "Alt+H"
      },
      "description": "Highlight selected text"
    },
    "bookmark-page": {
      "suggested_key": {
        "default": "Alt+B",
        "mac": "Alt+B"
      },
      "description": "Bookmark current page"
    }
  },
  "action": {
    "default_title": "Margin",
    "default_popup": "popup.html",
    "default_icon": {
      "16": "/icons/icon-16.png",
      "32": "/icons/icon-32.png",
      "48": "/icons/icon-48.png",
      "128": "/icons/icon-128.png"
    }
  },
  "sidebar_action": {
    "default_panel": "sidepanel.html",
    "default_icon": {
      "16": "/icons/icon-16.png",
      "32": "/icons/icon-32.png",
      "48": "/icons/icon-48.png"
    },
    "default_title": "Margin"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "hello@margin.at",
      "strict_min_version": "140.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "run_at": "document_idle",
      "js": [
        "content-scripts/content.js"
      ]
    }
  ]
}