Promql: Add clarifying note to Point.MarshalJSON
Promql: Add clarifying note to Point.MarshalJSON

Signed-off-by: beorn7 <91e32ae1d26bd312b370cf8378a5a83accca90a0@grafana.com>

prometheus/prometheus,prometheus/prometheus,keegancsmith/prometheus,keegancsmith/prometheus,prometheus/prometheus,keegancsmith/prometheus,prometheus/prometheus,prometheus/prometheus,keegancsmith/prometheus,keegancsmith/prometheus