docs(WEBPANEL.md): streamline and condense documentation for clarity

Simplify the WebPanel documentation by removing redundant
sections and focusing on key features and configurations.
The document now provides a concise overview of the WebPanel's
capabilities, installation, and configuration, making it easier
for users to quickly understand and set up the WebPanel.
This change aims to improve user experience by reducing
information overload and focusing on essential details.

Author: kzndotsh