Examine source code of Don't Show

{
  "manifest_version": 2,
  "name": "Don't Show",
  "description": "Hide sensitive information from websites ",
  "version": "1.0.5",
  "icons": {
    "16": "icons/16.png",
    "32": "icons/32.png",
    "48": "icons/48.png",
    "128": "icons/128.png"
  },
  "permissions": [
    "storage",
    "contextMenus",
    "activeTab"
  ],
  "options_page": "settings.html",
  "default_locale": "en",
  "browser_specific_settings": {
    "gecko": {
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      },
      "id": "{c8ca845d-3cde-41ab-8f2d-167a76b2f018}"
    }
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_title": "Don't Show",
    "default_popup": "popup.html"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "run_at": "document_start",
      "css": [
        "content-scripts/main.css"
      ],
      "js": [
        "content-scripts/main.js"
      ]
    },
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content-scripts/select.js"
      ]
    }
  ],
  "web_accessible_resources": [
    "content-scripts/select.css"
  ]
}