Examine source code of Shark Javascript Injector

{
  "manifest_version": 2,
  "name": "Javascript Injector",
  "version": "1.0.2",
  "browser_specific_settings": {
    "gecko": {
      "id": "javascript-injector@arturrosa.pl",
      "strict_min_version": "59.0a1"
    }
  },
  "description": "Evaluate Javascript code on pages at a given domain without being blocked by CSP. Create custom shortcuts with JS.",
  "icons": {
    "48": "icons/js-48.png",
    "128": "icons/js-128.png"
  },
  "permissions": [
    "storage",
    "<all_urls>"
  ],
  "browser_action": {
    "default_icon": {
      "48": "icons/js-48.png"
    },
    "default_title": "Javascript Injector",
    "default_popup": "dist/popup/index.html"
  },
  "background": {
    "scripts": [
      "dist/background/background.js"
    ]
  }
}