Examine source code of Soapbox Signer

{
  "manifest_version": 2,
  "name": "Soapbox Signer",
  "description": "A NIP-07 Nostr signer from Soapbox.",
  "version": "0.4.1",
  "icons": {
    "16": "icon/16.png",
    "32": "icon/32.png",
    "48": "icon/48.png",
    "64": "icon/64.png",
    "96": "icon/96.png",
    "128": "icon/128.png"
  },
  "permissions": [
    "storage",
    "nativeMessaging",
    "scripting",
    "*://relay.primal.net/*",
    "*://relay.damus.io/*",
    "*://relay.ditto.pub/*"
  ],
  "web_accessible_resources": [
    "nostr-mainworld.js"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "@signer.soapbox.pub",
      "data_collection_permissions": {
        "optional": [
          "personallyIdentifyingInfo",
          "authenticationInfo"
        ],
        "required": [
          "none"
        ]
      }
    }
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_title": "Soapbox Signer - popup",
    "default_popup": "popup.html"
  },
  "options_ui": {
    "open_in_tab": false,
    "page": "options.html"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*/*"
      ],
      "all_frames": true,
      "run_at": "document_start",
      "js": [
        "content-scripts/content.js"
      ]
    }
  ]
}