Examine source code of srcAddon

{
  "manifest_version": 2,
  "name": "srcAddon",
  "version": "1.0",
  "description": "Adds a red border to all webpages on srcmake.com",
  "icons": {
    "48": "fav-ls.png"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.srcmake.com/*"
      ],
      "js": [
        "srcborder.js"
      ]
    }
  ]
}