Examine source code of Deadname Remover

{
  "manifest_version": 2,
  "name": "Deadname Remover",
  "description": "A browser extension that replaces deadnames with chosen names (primarily for transgender and non-binary people).",
  "version": "2.3.0",
  "icons": {
    "16": "icon/trans16.png",
    "32": "icon/trans32.png",
    "48": "icon/trans48.png",
    "128": "icon/trans128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "deadname-remover@willhaycode.com",
      "strict_min_version": "58.0"
    }
  },
  "permissions": [
    "storage"
  ],
  "author": "Ari Gibson",
  "homepage_url": "https://github.com/arimgibson/Deadname-Remover",
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_title": "Deadname Remover Popup Settings",
    "default_popup": "popup.html"
  },
  "options_ui": {
    "open_in_tab": true,
    "page": "options.html"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "run_at": "document_start",
      "js": [
        "content-scripts/content.js"
      ]
    }
  ]
}