docs: fix invalid example in docs

[obycode]

Description

This just fixes some errors in one of the examples in the docs. No code changes.

Applicable issues

• N/A

Additional info (benefits, drawbacks, caveats)

Checklist

• Test coverage for new or modified code paths
• Changelog is updated
• Required documentation changes (e.g., docs/rpc/openapi.yaml and rpc-endpoints.md for v2 endpoints, event-dispatcher.md for new events)
• New clarity functions have corresponding PR in clarity-benchmarking repo
• New integration test(s) added to bitcoin-tests.yml

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (049db7e) 0.18% compared to head (37b50d1) 0.06%.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #4044      +/-   ##
==========================================
- Coverage    0.18%    0.06%   -0.12%     
==========================================
  Files         301      300       -1     
  Lines      277178   276083    -1095     
==========================================
- Hits          512      179     -333     
+ Misses     276666   275904     -762     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[CLAassistant]

All committers have signed the CLA.