Examine source code of NoteStamp

{
  "name": "NoteStamp",
  "version": "1.2.2",
  "description": "Annotate Your Video Lectures!",
  "manifest_version": 2,
  "browser_action": {
    "default_popup": "popup.html"
  },
  "commands": {
    "_execute_browser_action": {
      "suggested_key": {
        "default": "Ctrl+Shift+X",
        "mac": "Command+Shift+1",
        "windows": "Alt+Shift+X"
      },
      "description": "Open extension"
    }
  },
  "permissions": [
    "activeTab",
    "declarativeContent",
    "storage"
  ],
  "icons": {
    "16": "assets/logo16.png",
    "48": "assets/logo48.png",
    "128": "assets/logo128.png"
  }
}