message: fix: add content security policy to fix warning
diff: <html>
  <head>
  <meta charset="utf-8" />
  + <meta
  + http-equiv="Content-Security-Policy"
  + content="script-src 'self' 'unsafe-inline'"
  + />
  <title>Hello Electron React!</title>
  </head>
  <body>
  </body>
  <script>
  window.electron.ipcRenderer.once('ipc-example', (arg) => {
  - // eslint-disable-next-line no-console
  console.log(arg);
  });
  