Examine source code of Publicate Browser Extension

{
  "manifest_version": 2,
  "name": "Publicate Browser Add-on",
  "version": "1.0.4",
  "applications": {
    "gecko": {
      "id": "caedmon@publicate.it"
    }
  },
  "description": "Publicate - Create Beautiful Email Newsletters and Web Roundups in minutes, from content you find online.",
  "homepage_url": "https://publicate.it",
  "icons": {
    "16": "icons/publicate_16.png",
    "48": "icons/publicate_48.png",
    "128": "icons/publicate_128.png"
  },
  "background": {
    "scripts": [
      "src/bg/background.js"
    ],
    "persistent": true
  },
  "browser_action": {
    "default_icon": "icons/publicate_48.png",
    "default_title": "Publicate"
  },
  "permissions": [
    "https://*.publicate.it/*",
    "tabs"
  ],
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "js/jquery/jquery-3.3.1.min.js",
        "src/inject/inject.js"
      ]
    }
  ]
}