Examine source code of Replacer

{
  "manifest_version": 2,
  "name": "Replacer",
  "version": "1.1",
  "description": "Adds text replacement functionality to Firefox on macOS.",
  "icons": {
    "48": "src/assets/logo/extension-logo/replacer-48.png",
    "96": "src/assets/logo/extension-logo/replacer-96.png"
  },
  "browser_action": {
    "default_icon": {
      "16": "src/assets/logo/toolbar-button/replacer-16.png",
      "32": "src/assets/logo/toolbar-button/replacer-32.png",
      "64": "src/assets/logo/toolbar-button/replacer-64.png",
      "128": "src/assets/logo/toolbar-button/replacer-128.png"
    },
    "default_title": "Replacer",
    "default_popup": "src/popups/manage_replacements/manage_replacements.html"
  },
  "background": {
    "scripts": [
      "src/scripts/background_scripts/background.js"
    ],
    "persistent": false
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "src/scripts/content_scripts/replacer.js",
        "src/common/js/io.js"
      ]
    }
  ],
  "permissions": [
    "storage"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{1bda0ec8-58bc-4942-894b-22386d3a232f}"
    }
  }
}