Examine source code of QuickFillTimesheet

{
  "manifest_version": 2,
  "name": "QuickFillTimesheet",
  "version": "0.5",
  "description": "Tool to fill faster Replicon timesheets",
  "author": "Marc Ternisien",
  "options_ui": {
    "page": "options.html",
    "open_in_tab": true,
    "chrome_style": true
  },
  "icons": {
    "16": "assets/icon16.png",
    "48": "assets/icon48.png",
    "128": "assets/icon128.png"
  },
  "content_scripts": [
    {
      "matches": [
        "https://na9.replicon.com/*"
      ],
      "css": [
        "content.css"
      ],
      "js": [
        "jquery-3.4.1.min.js",
        "content.js"
      ]
    }
  ],
  "web_accessible_resources": [
    "script.js"
  ],
  "permissions": [
    "storage"
  ],
  "browser_action": {
    "default_icon": {
      "16": "assets/icon16.png",
      "48": "assets/icon48.png"
    },
    "default_popup": "options.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "quickfilltimesheet@quickfilltimesheet.com",
      "strict_min_version": "48.0"
    }
  }
}