Examine source code of JP-Hash

{
  "manifest_version": 2,
  "name": "JP-Hash",
  "version": "1.0",
  "description": "Converts any text input field content into its JP-Hash",
  "homepage_url": "https://www.kylheku.com/cgit/jp-hash/about",
  "icons": {
    "48": "jp-hash-48.png",
    "96": "jp-hash-96.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "jp-hash.js"
      ]
    }
  ],
  "browser_action": {
    "default_icon": "jp-hash-32.png",
    "default_title": "Calculate JP-Hash"
  },
  "commands": {
    "_execute_browser_action": {
      "suggested_key": {
        "default": "Alt+J"
      }
    }
  },
  "permissions": [
    "<all_urls>"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "json-hash@kylheku.com"
    }
  }
}