Examine source code of Readalix: Read Aloud & Text to Speech

{
  "manifest_version" : 3 ,
  "name" : "__MSG_extName__" ,
  "short_name" : "Readalix",
  "description" : "__MSG_extDescription__" ,
  "default_locale" : "en" ,
  "icons" : {
    "16" : "icon16.png",
    "48" : "icon48.png",
    "128" : "icon128.png"
  },
  "action" : {
    "default_popup" : "popup.html",
    "default_icon" : "icon128.png",
    "default_title" : "Readalix"
  },
  "background" : {
    "scripts" : [
      "background.js" 
    ],
    "type" : "module" 
  },
  "commands" : {
    "snip": {
      "description" : "__MSG_shortcut_snip__" 
    }
  },
  "content_scripts" : [
    {
      "matches" : [
        "<all_urls>" 
      ],
      "js" : [
        "content-script.js" 
      ],
      "run_at" : "document_idle" ,
      "all_frames" : true 
    },
    {
      "matches" : [
        "<all_urls>" 
      ],
      "js" : [
        "snip-first.js" 
      ],
      "run_at" : "document_start" 
    },
    {
      "matches" : [
        "https://extensionpay.com/*" 
      ],
      "js" : [
        "extpay-content.js" 
      ],
      "run_at" : "document_start" 
    }
  ],
  "permissions" : [
    "scripting" ,
    "storage" ,
    "unlimitedStorage" ,
    "contextMenus" ,
    "declarativeNetRequestWithHostAccess" 
  ],
  "host_permissions" : [
    "<all_urls>" 
  ],
  "declarative_net_request" : {
    "rule_resources": [
      {
        "id": "edge-tts",
        "enabled": true,
        "path": "rules-edge.json"
      }
    ]
  },
  "content_security_policy" : {
    "extension_pages": "script-src 'self' 'wasm-unsafe-eval'; object-src 'self'"
  },
  "version" : "1.21.1",
  "page_action" : {
    "default_icon" : {
      "16" : "icon16.png",
      "48" : "icon48.png"
    },
    "default_title" : "__MSG_pdfNoteOpen__" ,
    "show_matches": [
      "*://*/*.pdf",
      "*://*/*.pdf?*",
      "*://*/*.PDF",
      "file:///*.pdf"
    ]
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "readalix@readalix.com",
      "strict_min_version": "140.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ],
        "optional": [
          "technicalAndInteraction"
        ]
      }
    }
  }
}