Examine source code of Word Tail Extractor Addon

{
  "manifest_version": 2,
  "name": "Word Tail Extractor Addon",
  "version": "1.0.1",
  "description": "Display the ending characters of words.",
  "browser_action": {
    "default_title": "Word Tails",
    "default_popup": "popup.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "extract-word-tails-1dac2b88-24f1-433f-8fc6-5f94365dbf1b@example.com",
      "strict_min_version": "58.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}