Missing icon on Toggle Theme button

[tino1501]

Describe the bug
Missing icon on Toggle Theme button.

To Reproduce
Steps to reproduce the behavior:

1. Go to demo page at https://readme-typing-svg.demolab.com/demo/
2. Look at button on top-right.

Desktop (please complete the following information):

• OS: Linux Mint.
• Browser: Chrome 141.0.7390.54, Brave 1.84.141 - Chromium: 142.0.7444.176.