Examine source code of MastoShare v2

{
  "manifest_version": 2,
  "name": "MastoShare",
  "version": "1.0",
  "description": "Share links to Mastodon in one click!",
  "permissions": [
    "activeTab",
    "contextMenus"
  ],
  "background": {
    "scripts": [
      "popup.js"
    ]
  },
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": {
      "48": "icon.png"
    }
  },
  "icons": {
    "48": "icon.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{1f194937-123b-4123-b7d4-c5aac52753d4}"
    }
  }
}