Clarify: all rules in a group are concomitant
Improve the documentation to clarify the differences beetween rules in a
group and outside a group.
@@ -45,8 +45,9 @@ dashboards, which need to query the same expression repeatedly every time they
refresh.
Recording and alerting rules exist in a rule group. Rules within a group are
-run sequentially at a regular interval. The names of recording rules
-must be [valid metric names](https://prometheus.io/docs/concepts/data_model/#metric-names-and-labels).
+run sequentially at a regular interval, with the same evaluation time.
+The names of recording rules must be
+[valid metric names](https://prometheus.io/docs/concepts/data_model/#metric-names-and-labels).
The names of alerting rules must be
[valid label values](https://prometheus.io/docs/concepts/data_model/#metric-names-and-labels).
