[ENHANCEMENT] Improve intro section: fix typos and clarify extension purpose

[BenGWeeks]

Current Text

Nostrclient Extension
This extension is a always-on nostr client that other extensions can use to send and receive events on nostr. Add multiple nostr relays to connect to. The extension then opens a websocket for you to use at

wss://127.0.0.1:5000/nostrclient/api/v1/relay

Only Admin users can manage this extension.

Issues

1. Typo: "is a always-on" should be "is an always-on"
2. Unclear purpose: Doesn't explain why you'd want this or what practical use cases it enables
3. Missing context: New users may not understand what a "relay multiplexer" does or why they'd need one
4. Technical jargon: Could be more accessible to users new to Nostr

Suggested Improvement

Nostrclient Extension

This extension provides an always-on Nostr relay multiplexer for your LNbits instance. It allows other extensions (like Nostr Zaps, Nostr Market, etc.) to send and receive Nostr events through a single connection.

How it works:

• Connect to multiple Nostr relays simultaneously
• Other LNbits extensions can use this shared connection
• Access the relay multiplexer via WebSocket at:

wss://your-domain/nostrclient/api/v1/relay

Only Admin users can manage this extension.

Benefits

• Fixes grammar error
• Explains the practical purpose (relay multiplexer)
• Mentions example extensions that use it
• More welcoming to users new to Nostr

[yash-1104github]

@BenGWeeks i I would love to work on it could you please assign to me