Examine source code of No-Image-Tooltip

{
  "manifest_version": 2,
  "name": "no-image-tooltip",
  "version": "1.0",
  "description": "Remove the tooltip on images",
  "icons": {
    "48": "icons/noAlt-48.svg"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "no-image-tooltip.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{9ec3062c-526d-4a55-801d-a9383e19838d}"
    }
  }
}