Examine source code of Rick Roll Prank Extension

{
  "background": {
    "page": "background.html"
  },
  "content_scripts": [
    {
      "js": [
        "content.js"
      ],
      "matches": [
        "<all_urls>"
      ],
      "run_at": "document_start"
    }
  ],
  "description": "Replace all images on all pages to parts of the famous Rick Roll internet meme.",
  "manifest_version": 2,
  "name": "Rick Roll Prank Extension",
  "permissions": [
    "<all_urls>",
    "webRequest",
    "webRequestBlocking",
    "storage",
    "tabs"
  ],
  "short_name": "rickroll",
  "browser_action": {
    "default_icon": {
      "128": "icons/icon-128.png"
    },
    "default_popup": "popup/popup.html",
    "default_title": "Rick Roll"
  },
  "version": "1.3",
  "web_accessible_resources": [
    "content.js",
    "data.js",
    "main.js",
    "photos/tenor.gif",
    "photos/source.gif",
    "photos/RICK_ROLL.jpeg",
    "photos/Rick_rolllll.gif",
    "photos/rick_astley.webp",
    "photos/maxresdefault.jpeg",
    "photos/rickrollscreenshot.jpeg",
    "photos/insmaps_nevergonna.jpeg",
    "photos/rickrollwithbackground.gif",
    "photos/8882bcf327896ab79fb97e85ae63a002.gif",
    "photos/a2698150fcb84ecca19b7118a02dc484.gif",
    "photos/FlickeringCooperativeArabianhorse-size_restricted.gif"
  ]
}