Same content, restructured for scanning: tables instead of long
paragraphs (credentials, troubleshooting, env vars), shorter sentences,
deep rationale trimmed to a phrase + issue reference instead of inline
essays. Cut from 258 to 135 lines.
Added assets/weathermap-pipeline.svg showing the IPFabric/Prometheus ->
generator -> merge (with the manual base) -> Grafana flow, referenced at
the top of the README.