docs: update metric names stats description (#8483)

* add version since feature is available
* add cluster endpoint paths

### Describe Your Changes

Please provide a brief description of the changes you made. Be as
specific as possible to help others understand the purpose and impact of
your modifications.

### Checklist

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- [ ] My change adheres [VictoriaMetrics contributing
guidelines](https://docs.victoriametrics.com/contributing/).

Signed-off-by: f41gh7 <nik@victoriametrics.com>

docs/README.md

@@ -463,11 +463,11 @@ due to [replication](#replication) or [rerouting](https://docs.victoriametrics.c
 
 ### Track ingested metrics usage
 
-VictoriaMetrics provides the ability to record statistics of fetched [metric names](https://docs.victoriametrics.com/keyconcepts/#structure-of-a-metric) during [querying](https://docs.victoriametrics.com/keyconcepts/#query-data). This feature can be enabled via the flag `--storage.trackMetricNamesStats` (disabled by default) on  a single-node VictoriaMetrics or [vmstorage](https://docs.victoriametrics.com/cluster-victoriametrics/#architecture-overview). Querying a metric with non-matching filters doesn't increase the counter for this particular metric name.
+VictoriaMetrics provides the ability to record statistics of fetched [metric names](https://docs.victoriametrics.com/keyconcepts/#structure-of-a-metric) during [querying](https://docs.victoriametrics.com/keyconcepts/#query-data) {{% available_from "v1.113.0" %}}. This feature can be enabled via the flag `--storage.trackMetricNamesStats` (disabled by default) on  a single-node VictoriaMetrics or [vmstorage](https://docs.victoriametrics.com/cluster-victoriametrics/#architecture-overview). Querying a metric with non-matching filters doesn't increase the counter for this particular metric name.
 For example, querying for `vm_log_messages_total{level!="info"}` won't increment usage counter for `vm_log_messages_total` if there are no `{level="error"}` or `{level="warning"}` series yet.
 VictoriaMetrics tracks metric names query statistics for `/api/v1/query`, `/api/v1/query_range`, `/render`, `/federate` and `/api/v1/export` API calls.
 
-To get metric names usage statistics, use the `/prometheus/api/v1/status/metric_names_stats` API endpoint. It accepts the following query parameters:
+To get metric names usage statistics, use the `/prometheus/api/v1/status/metric_names_stats` API endpoint for a single-node VictoriaMetrics (or at `http://<vmselect>:8481/select/<accountID>/prometheus/api/v1/status/metric_names_stats` in [cluster version of VictoriaMetrics](https://docs.victoriametrics.com/cluster-victoriametrics/)). It accepts the following query parameters:
 
 * `limit` - integer value to limit the number of metric names in response. By default, API returns 1000 records.
 * `le` -  `less than or equal`, is an integer threshold for filtering metric names by their usage count in queries. For example, with `?le=1` API returns metric names that were queried <=1 times.
@@ -510,7 +510,7 @@ VictoriaMetrics exposes the following metrics for the metric name tracker:
 
 An alerting rule with query `vm_cache_size_bytes{type="storage/metricNamesStatsTracker"} \ vm_cache_size_max_bytes{type="storage/metricNamesStatsTracker"} > 0.9` can be used to notify the user of cache utilization exceeding 90%.
 
-The metric name tracker state can be reset via the API endpoint /api/v1/admin/status/metric_names_stats/reset or  
+The metric name tracker state can be reset via the API endpoint `/api/v1/admin/status/metric_names_stats/reset` for a single-node VictoriaMetrics (or at `http://<vmselect>:8481/admin/api/v1/admin/status/metric_names_stats/reset` in [cluster version of VictoriaMetrics](https://docs.victoriametrics.com/cluster-victoriametrics/)) or
 via [cache removal](#cache-removal) procedure.
 
 ## How to apply new config to VictoriaMetrics