Examine source code of Jira Branch Creator

{
  "manifest_version": 2,
  "name": "Jira Branch Creator",
  "version": "1.1",
  "description": "Plugin to create git branch name from Jira ticket",
  "permissions": [
    "clipboardWrite",
    "activeTab"
  ],
  "icons": {
    "48": "icons/Branch48.png",
    "96": "icons/Branch96.png"
  },
  "browser_action": {
    "default_icon": "icons/Branch48.png",
    "theme_icons": [
      {
        "light": "icons/Branch32-light.png",
        "dark": "icons/Branch32.png",
        "size": 32
      }
    ],
    "default_title": "Jira Branch Creator",
    "default_popup": "popup/branchify.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{48cc3143-dc72-4c19-811f-ac2406390867}"
    }
  }
}