Examine source code of e-kbd-nav

{
  "manifest_version": 2,
  "name": "e-kbd-nav",
  "version": "1.0.2",
  "description": "Enables keyboard navigation on e* pages",
  "homepage_url": "https://github.com/cwillsey06/e-kbd-nav",
  "icons": {
    "32": "icons/icon32.png",
    "48": "icons/icon48.png",
    "96": "icons/icon96.png"
  },
  "browser_action": {
    "default_icon": "icons/icon32.png",
    "default_title": "e-kbd-nav",
    "default_popup": "public/index.html"
  },
  "content_scripts": [
    {
      "matches": [
        "https://e621.net/*",
        "https://e926.net/*"
      ],
      "js": [
        "index.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{b3869e0f-b314-45e0-aa2a-a416f6cd4276}"
    }
  }
}