Examine source code of Markdown Reader

{
  "name": "__MSG_ext_name__",
  "version": "2.12.12",
  "author": "Bener",
  "manifest_version": 2,
  "description": "__MSG_ext_desc__",
  "default_locale": "en",
  "icons": {
    "16": "images/logo-stroke.png",
    "32": "images/logo-stroke.png",
    "48": "images/logo-stroke.png",
    "128": "images/logo-stroke.png",
    "512": "images/logo-stroke.png"
  },
  "web_accessible_resources": [
    "css/*",
    "fonts/*",
    "images/*"
  ],
  "background": {
    "scripts": [
      "js/background.js"
    ]
  },
  "browser_action": {
    "default_title": "md-reader",
    "default_popup": "popup.html"
  },
  "content_scripts": [
    {
      "js": [
        "js/content.js"
      ],
      "css": [
        "css/content.css"
      ],
      "matches": [
        "*://*/*.md",
        "*://*/*.mdx",
        "*://*/*.mkd",
        "*://*/*.markdown",
        "*://*/*.MD",
        "*://*/*.MDX",
        "*://*/*.MKD",
        "*://*/*.MARKDOWN",
        "file://*/*.md",
        "file://*/*.mdx",
        "file://*/*.mkd",
        "file://*/*.markdown",
        "file://*/*.MD",
        "file://*/*.MDX",
        "file://*/*.MKD",
        "file://*/*.MARKDOWN",
        "*://*/*.md?*",
        "*://*/*.mdx?*",
        "*://*/*.mkd?*",
        "*://*/*.markdown?*",
        "*://*/*.MD?*",
        "*://*/*.MDX?*",
        "*://*/*.MKD?*",
        "*://*/*.MARKDOWN?*",
        "file://*/*.md?*",
        "file://*/*.mdx?*",
        "file://*/*.mkd?*",
        "file://*/*.markdown?*",
        "file://*/*.MD?*",
        "file://*/*.MDX?*",
        "file://*/*.MKD?*",
        "file://*/*.MARKDOWN?*"
      ]
    }
  ],
  "commands": {
    "toggleSide": {
      "description": "__MSG_command_toggle_side__",
      "suggested_key": {
        "default": "Alt+Shift+B"
      }
    },
    "toggleCentered": {
      "description": "__MSG_command_toggle_centered__",
      "suggested_key": {
        "default": "Alt+Shift+C"
      }
    },
    "toggleRefresh": {
      "description": "__MSG_command_toggle_refresh__",
      "suggested_key": {
        "default": "Alt+Shift+R"
      }
    },
    "toggleTheme": {
      "description": "__MSG_command_toggle_theme__",
      "suggested_key": {
        "default": "Alt+Shift+T"
      }
    }
  },
  "permissions": [
    "storage"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{f3ee08f8-d4d8-4095-8096-4bb784d082f9}"
    }
  }
}