Examine source code of Send to Aria2 WE

{
  "manifest_version": 2,
  "name": "Send to Aria2 WE",
  "description": "Send The Download Link to Your Aria2 server's json-rpc api.\nThe api address should be configed at first in the preference page, and the aria2 rpc-secret is also supported.",
  "version": "0.3.2resigned1",
  "homepage_url": "https://github.com/wadefelix/SendToAria2",
  "developer": {
    "name": "Ren Wei"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content-script.js"
      ],
      "run_at": "document_end"
    }
  ],
  "permissions": [
    "contextMenus",
    "activeTab",
    "tabs",
    "storage",
    "notifications"
  ],
  "options_ui": {
    "page": "options.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{9cc772b3-94a0-42b7-a777-bc9ff32726b7}"
    }
  }
}