Examine source code of Check grammar and style

{
  "manifest_version": 2,
  "name": "LanguageTool Grammar Checker (helper)",
  "version": "1.0.0",
  "description": "Check grammar and style using LanguageTool-compatible API. Configure endpoint/API key in options.",
  "permissions": [
    "storage",
    "activeTab",
    "contextMenus",
    "tabs"
  ],
  "browser_action": {
    "default_title": "LanguageTool Grammar Checker",
    "default_popup": "popup.html"
  },
  "options_ui": {
    "page": "options.html",
    "open_in_tab": true
  },
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "applications": {
    "gecko": {
      "id": "languagetool-grammar-checker@example.com"
    }
  }
}