docs: add make command for docs version update (#7430)

### Describe Your Changes

added make target, which updates `{{% available_from "#" %}}` shortcode
to `{{% available_from "$(PKG_TAG)" %}}` if PKG_TAG matches expression
`v.*`. `{{% available_from %}}` shortcode was introduced in
https://github.com/VictoriaMetrics/vmdocs/pull/89 to show a reference to
a version in a changelog since which a feature was introduced

related issue
https://github.com/VictoriaMetrics/VictoriaMetrics/issues/7376

### Checklist

The following checks are **mandatory**:

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

docs/Makefile

@@ -21,6 +21,18 @@ docs-debug: docs docs-image
 		-p 1313:1313 \
 		-v ./docs:/opt/docs/content vmdocs-docker-package
 
+docs-update-version: docs-image
+	$(if $(filter v%,$(PKG_TAG)), \
+		docker run \
+			--rm \
+			--entrypoint /usr/bin/find \
+			--name vmdocs-docker-container \
+			-v ./docs:/opt/docs/content vmdocs-docker-package \
+				content \
+					-regex ".*\.md" \
+					-exec sed -i 's/{{% available_from "#" %}}/{{% available_from "$(PKG_TAG)" %}}/g' {} \;, \
+		$(info "Skipping docs version update, invalid $$PKG_TAG: $(PKG_TAG)"))
+
 docs-images-to-webp: docs-image
 	docker run \
 		--rm \

docs/VictoriaLogs/data-ingestion/DataDogAgent.md

@@ -49,4 +49,4 @@ See also:
 
 - [Data ingestion troubleshooting](https://docs.victoriametrics.com/victorialogs/data-ingestion/#troubleshooting).
 - [How to query VictoriaLogs](https://docs.victoriametrics.com/victorialogs/querying/).
-- [Docker-compose demo for Datadog integration with VictoriaLogs](https://github.com/VictoriaMetrics/VictoriaMetrics/tree/master/deployment/docker/victorialogs/datadog).
+- [Docker-compose demo for Datadog integration with VictoriaLogs](https://github.com/VictoriaMetrics/VictoriaMetrics/tree/master/deployment/docker/victorialogs/datadog-agent).

docs/VictoriaLogs/data-ingestion/README.md

@@ -10,6 +10,7 @@
 - Telegraf - see [these docs](https://docs.victoriametrics.com/victorialogs/data-ingestion/telegraf/).
 - OpenTelemetry Collector - see [these docs](https://docs.victoriametrics.com/victorialogs/data-ingestion/opentelemetry/).
 - Journald - see [these docs](https://docs.victoriametrics.com/victorialogs/data-ingestion/journald/).
+- DataDog - see [these docs](https://docs.victoriametrics.com/victorialogs/data-ingestion/datadog-agent/).
 
 The ingested logs can be queried according to [these docs](https://docs.victoriametrics.com/victorialogs/querying/).
 
@@ -322,5 +323,5 @@ Here is the list of log collectors and their ingestion formats supported by Vict
 | [Telegraf](https://docs.victoriametrics.com/victorialogs/data-ingestion/telegraf/) | [Yes](https://github.com/influxdata/telegraf/tree/master/plugins/outputs/elasticsearch) | [Yes](https://github.com/influxdata/telegraf/tree/master/plugins/outputs/http) | [Yes](https://github.com/influxdata/telegraf/tree/master/plugins/outputs/loki) | [Yes](https://github.com/influxdata/telegraf/blob/master/plugins/outputs/syslog) | Yes | No | No |
 | [Fluentd](https://docs.victoriametrics.com/victorialogs/data-ingestion/fluentd/) | [Yes](https://github.com/uken/fluent-plugin-elasticsearch) | [Yes](https://docs.fluentd.org/output/http) | [Yes](https://grafana.com/docs/loki/latest/send-data/fluentd/) | [Yes](https://github.com/fluent-plugins-nursery/fluent-plugin-remote_syslog) | No | No | No |
 | [Journald](https://docs.victoriametrics.com/victorialogs/data-ingestion/journald/) | No | No | No | No | No | Yes | No |
-| [DataDog Agent](https://docs.victoriametrics.com/VictoriaLogs/data-ingestion/DataDogAgent.html) | No | No | No | No | No | No | Yes |
+| [DataDog Agent](https://docs.victoriametrics.com/VictoriaLogs/data-ingestion/datadog-agent) | No | No | No | No | No | No | Yes |