Examine source code of Read Aloud Extension

{
  "manifest_version": 3,
  "name": "Read Aloud Extension",
  "version": "1.0.1",
  "description": "A Text-to-Speech extension that reads web pages aloud.",
  "author": "realsanjeev",
  "homepage_url": "https://bhandarisanjeev.com.np",
  "permissions": [
    "activeTab",
    "scripting",
    "storage",
    "contextMenus"
  ],
  "optional_host_permissions": [
    "http://*/",
    "https://*/",
    "file://*/*"
  ],
  "action": {
    "default_popup": "ui/popup.html",
    "default_icon": {
      "16": "assets/icons/icon-16.png",
      "48": "assets/icons/icon-48.png",
      "128": "assets/icons/icon-128.png"
    }
  },
  "options_ui": {
    "page": "ui/options.html",
    "open_in_tab": true
  },
  "background": {
    "scripts": [
      "scripts/background.js"
    ]
  },
  "icons": {
    "16": "assets/icons/icon-16.png",
    "48": "assets/icons/icon-48.png",
    "128": "assets/icons/icon-128.png"
  },
  "content_security_policy": {
    "extension_pages": "script-src 'self'; object-src 'self';"
  },
  "commands": {
    "_execute_action": {
      "description": "Open extension popup"
    },
    "play_stop": {
      "suggested_key": {
        "default": "Alt+O"
      },
      "description": "Play/Stop"
    },
    "pause_resume": {
      "suggested_key": {
        "default": "Alt+P"
      },
      "description": "Pause/Resume"
    },
    "forward": {
      "suggested_key": {
        "default": "Alt+Period"
      },
      "description": "Next sentence"
    },
    "rewind": {
      "suggested_key": {
        "default": "Alt+Comma"
      },
      "description": "Previous sentence"
    },
    "next_paragraph": {
      "description": "Next paragraph"
    },
    "prev_paragraph": {
      "description": "Previous paragraph"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "speak-aloud@realsanjeev.com",
      "strict_min_version": "128.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}