Examine source code of Make Text Bold

{
  "manifest_version": 2,
  "name": "Make Text Bold",
  "version": "1.0",
  "description": "Adds a make text bold menu item to the context menu.",
  "permissions": [
    "contextMenus",
    "activeTab"
  ],
  "background": {
    "scripts": [
      "background_script.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ],
      "run_at": "document_idle"
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "maketextbold@zersche.local",
      "strict_min_version": "109.0"
    }
  }
}