Examine source code of abcTajpu

{
  "manifest_version": 2,
  "name": "Abctajpu",
  "version": "2.6",
  "default_locale": "en",
  "description": "àβĉ_TAJPU __MSG_pri__",
  "author": "lingvo.org",
  "homepage_url": "https://lingvo.org/abctajpu",
  "applications": {
    "gecko": {
      "id": "{15a7ef52-8a77-426e-9e17-e21af257d7c8}",
      "strict_min_version": "63.0"
    }
  },
  "icons": {
    "32": "piktogramoj/klavaro-32.png"
  },
  "permissions": [
    "tabs",
    "contextMenus",
    "storage",
    "clipboardRead",
    "clipboardWrite",
    "<all_urls>"
  ],
  "options_ui": {
    "page": "opcioj/opcioj.html"
  },
  "background": {
    "persistent": true,
    "scripts": [
      "abctajpu.js",
      "fono/fono.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "*://*/*"
      ],
      "all_frames": true,
      "js": [
        "abctajpu.js",
        "enhavo/tajpilo2.js"
      ]
    }
  ],
  "commands": {
    "_execute_browser_action": {
      "suggested_key": {
        "default": "Alt+K"
      }
    },
    "abctajpu2_ordono_x": {
      "suggested_key": {
        "default": "Alt+X"
      },
      "description": "a=b, a alt-x → b"
    },
    "abctajpu2_ordono_7": {
      "suggested_key": {
        "default": "Ctrl+Shift+7"
      },
      "description": "tajpi por tondujo"
    }
  },
  "browser_action": {
    "default_icon": {
      "32": "piktogramoj/klavaro-32.png"
    },
    "default_title": "abcTajpu",
    "default_popup": "shprucoj/klavaro.html"
  }
}