Examine source code of RezkaAdBlock

{
  "manifest_version": 2,
  "name": "RezkaAdBlock",
  "description": "custom addon",
  "version": "0.0.1",
  "icons": {
    "64": "icons/icon.png"
  },
  "permissions": [
    "webRequest",
    "webRequestBlocking",
    "<all_urls>"
  ],
  "background": {
    "scripts": [
      "backgroundScript.js"
    ]
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{6e11e546-776e-4370-a686-25c1cf36f38c}"
    }
  }
}