Examine source code of ztr

{
  "manifest_version": 2,
  "name": "ztr",
  "version": "1.0.19",
  "icons": {
    "16": "assets/icons/16.png",
    "32": "assets/icons/32.png",
    "48": "assets/icons/48.png",
    "128": "assets/icons/128.png"
  },
  "description": "transliterator phur hindi bengali punjabi guzrati malayalam telugu tamil kannada oriya.",
  "homepage_url": "https://gitlab.com/zava810/ztr",
  "short_name": "ztr",
  "permissions": [
    "activeTab",
    "storage",
    "http://*/*",
    "https://*/*"
  ],
  "content_security_policy": "script-src 'self'; object-src 'self'",
  "author": "viml kumar",
  "applications": {
    "gecko": {
      "id": "zinglish@kakao.com"
    }
  },
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": {
      "16": "assets/icons/16.png",
      "19": "assets/icons/19.png",
      "32": "assets/icons/32.png",
      "38": "assets/icons/38.png",
      "48": "assets/icons/48.png",
      "64": "assets/icons/64.png",
      "128": "assets/icons/128.png",
      "512": "assets/icons/512.png"
    },
    "default_title": "ztr",
    "browser_style": false
  },
  "options_ui": {
    "page": "options.html",
    "open_in_tab": true
  },
  "background": {
    "scripts": [
      "js/background.bundle.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "http://*/*",
        "https://*/*",
        "file://*/*"
      ],
      "js": [
        "js/contentScript.bundle.js"
      ],
      "css": [
        "css/contentScript.css"
      ]
    }
  ]
}