Examine source code of The Forgetter

{
  "manifest_version": 2,
  "name": "The Forgetter",
  "version": "1.0",
  "homepage_url": "https://github.com/Pachandre/the-forgetter",
  "description": "This extension clears urls that match keywords (set in extension) from history. Extension does not clear cookie and any other information",
  "icons": {
    "16": "./src/img/icon16.png",
    "32": "./src/img/icon32.png",
    "48": "./src/img/icon48.png",
    "64": "./src/img/icon64.png",
    "96": "./src/img/icon96.png",
    "128": "./src/img/icon128.png",
    "256": "./src/img/icon256.png",
    "512": "./src/img/icon512.png"
  },
  "incognito": "not_allowed",
  "browser_action": {
    "default_icon": {
      "16": "./src/img/icon16.png",
      "32": "./src/img/icon32.png",
      "48": "./src/img/icon48.png",
      "64": "./src/img/icon64.png",
      "96": "./src/img/icon96.png",
      "128": "./src/img/icon128.png",
      "256": "./src/img/icon256.png",
      "512": "./src/img/icon512.png"
    },
    "default_title": "The Forgetter",
    "default_popup": "./src/html/popup.html"
  },
  "permissions": [
    "history",
    "storage"
  ],
  "background": {
    "page": "./src/html/backgroundPage.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{9f257b85-e855-4180-929f-726387bf89d6}"
    }
  }
}