Client

Adds to global config:

[http "https://<host>/<owner>/repo"]
  extraHeader = "Authorization: Nostr $(./create_nostr_auth_header.sh)"
  

TODO:

• add signing for header generation
• add id for header generation
• add base64 encofing for header generation
• add key retrieval mechanism
• add script for extendign config file for speicific urls