Unleashed 0.1.7

Nostr mode improvements:

- Implemented relevance score threshold when searching for a topic, i.e. you should see less irrelevant results when you ask about some topic or keywords.

- Chat bot now has some knowedge about note authors and dates (TBD how reliable this is)

- Allow specifying USD amount on LN invoice – for wallets that don't support 0-amount invoices

- Fix typo on home page