vmui: clarify the info for TotalSeries stat (#7271)

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specific as possible to help others understand the purpose and impact of
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- [ ] My change adheres [VictoriaMetrics contributing
guidelines](https://docs.victoriametrics.com/contributing/).

Signed-off-by: hagen1778 <roman@victoriametrics.com>

app/vmui/packages/vmui/src/pages/CardinalityPanel/CardinalityTotals/CardinalityTotals.tsx

@@ -41,10 +41,10 @@ const CardinalityTotals: FC<CardinalityTotalsProps> = ({
       value: totalSeries.toLocaleString("en-US"),
       dynamic: (!totalSeries || !totalSeriesPrev || isPrometheus) ? "" : `${dynamic.toFixed(2)}%`,
       display: !focusLabel,
-      info: `The total number of active time series. 
+      info: `The total number of unique time series for a selected day.
              A time series is uniquely identified by its name plus a set of its labels. 
              For example, temperature{city="NY",country="US"} and temperature{city="SF",country="US"} 
-             are two distinct series, since they differ by the city label.`
+             are two distinct series, since they differ by the "city" label.`
     },
     {
       title: "Percentage from total",