Examine source code of Joplin Web Clipper

{
  "manifest_version": 2,
  "name": "Joplin Web Clipper",
  "version": "2.11.2",
  "description": "Capture and save web pages and screenshots from your browser to Joplin.",
  "homepage_url": "https://joplinapp.org",
  "content_security_policy": "script-src 'self'; object-src 'self'",
  "icons": {
    "32": "icons/32.png",
    "48": "icons/48.png",
    "96": "icons/96.png"
  },
  "permissions": [
    "activeTab",
    "tabs",
    "http://*/",
    "https://*/",
    "<all_urls>",
    "storage"
  ],
  "browser_action": {
    "default_icon": "icons/32.png",
    "default_title": "Joplin Web Clipper",
    "default_popup": "popup/build/index.html"
  },
  "commands": {
    "_execute_browser_action": {
      "suggested_key": {
        "default": "Alt+Shift+J"
      }
    },
    "clipCompletePage": {
      "suggested_key": {
        "default": "Alt+Shift+C"
      },
      "description": "Clip complete page (uses last selected notebook)"
    },
    "clipCompletePageHtml": {
      "description": "Clip complete page (HTML) (uses last selected notebook)"
    },
    "clipSimplifiedPage": {
      "description": "Clip simplified page (uses last selected notebook)"
    },
    "clipUrl": {
      "description": "Clip url (uses last selected notebook)"
    },
    "clipSelection": {
      "description": "Clip selection (uses last selected notebook)"
    }
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "applications": {
    "gecko": {
      "id": "{8419486a-54e9-11e8-9401-ac9e17909436}"
    }
  }
}