Examine source code of Strict Spellcheck

{
  "manifest_version": 2,
  "name": "Strict Spellcheck",
  "version": "1.0",
  "description": "Highlight misspelled words on webpages.",
  "browser_specific_settings": {
    "gecko": {
      "id": "strictspellchecker@example.com",
      "data_collection_permissions": {
        "required": [
          "none"
        ],
        "websites": "none",
        "user_data": "none"
      }
    }
  },
  "permissions": [
    "activeTab",
    "storage",
    "<all_urls>"
  ],
  "browser_action": {
    "default_popup": "spch_popup.html",
    "default_icon": {
      "16": "icon.png",
      "48": "icon.png",
      "128": "icon.png"
    }
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ],
      "css": [
        "spch_style.css"
      ],
      "run_at": "document_idle"
    }
  ],
  "web_accessible_resources": [
    "words.txt"
  ]
}