docs/managed-victoriametrics: use webp format to reduce image size (#5206)

(cherry picked from commit d3f919df3e)
Signed-off-by: hagen1778 <roman@victoriametrics.com>

docs/Makefile

@@ -20,3 +20,16 @@ docs-up-docker:
 		-p 4000:4000 \
 		-v $(PWD):/srv/jekyll \
 		jekyll/jekyll:3.8 jekyll serve --livereload
+
+docs-images-to-webp:
+	docker run -it --rm -v \
+		$(PWD)/$(PATH_TO_IMAGES):/data \
+		elswork/cwebp \
+		find ./ -type f -name '*.$(IMAGES_EXTENSION)' -exec sh -c 'cwebp -q ${IMAGE_QUALITY} -m 6 $$1 -o "$${1%.png}.webp"' _ {} \;
+
+docs-remove-old-images:
+	rm -f $(PWD)/$(PATH_TO_IMAGES)/*.$(IMAGES_EXTENSION)
+
+docs-change-images: \
+	docs-images-to-webp \
+	docs-remove-old-images

docs/managed-victoriametrics/alerting-vmalert-managed-victoria-metrics.md

@@ -13,7 +13,7 @@ aliases:
 
 This guide explains the different ways in which you can use vmalert in conjunction with Managed VictoriaMetrics
 
-<img src="alerting-vmalert-managed-victoria-metrics-setup.png">
+<img src="alerting-vmalert-managed-victoria-metrics-setup.webp">
 
 ## Preconditions 
 
@@ -55,14 +55,14 @@ For instructions on how to create tokens, please refer to this section of the [d
 
 #### Single-Node
 
-<img src="alerting_token_created_single.png">
-<img src="alerting_copy_datasource_single.png">
+<img src="alerting_token_created_single.webp">
+<img src="alerting_copy_datasource_single.webp">
 
 #### Cluster
 
-<img src="alerting_token_created_cluster.png">
-<img src="alerting_copy_reading_datasource_cluster.png">
-<img src="alerting_copy_writing_datasource_cluster.png">
+<img src="alerting_token_created_cluster.webp">
+<img src="alerting_copy_reading_datasource_cluster.webp">
+<img src="alerting_copy_writing_datasource_cluster.webp">
 
 ### vmalert configuration 
 

docs/managed-victoriametrics/how-to-monitor-k8s.md

@@ -46,7 +46,7 @@ Install the Helm chart in a custom namespace
    ```
    </div>
    You can find your access token on the "Access" tab of your deployment
-   <img src="kubernetes_monitoring.png" width="800">
+   <img src="kubernetes_monitoring.webp" width="800">
 1. Set up a Helm repository using the following commands:
    <div class="with-copy" markdown="1">
    ```bash
@@ -129,7 +129,7 @@ Connect to grafana and create your datasource
    Choose VictoriaMetrics or Prometheus as datasource type. Make sure you made this datasource as default for dashboards to work.
    > You can find token and URL in your deployment, on Access tab
   
-   <img src="how-to-monitor-k8s_datasource.png" width="800">
+   <img src="how-to-monitor-k8s_datasource.webp" width="800">
 
 ## Test it