[Request]: Sanity check of images appearance

### Description

Harmonize the size of images that look too big, for example:
- [Stream any log file](https://observability-docs_bk_4532.docs-preview.app.elstc.co/guide/en/serverless/current/observability-stream-log-files.html)
- [Quickstart: Monitor your Kubernetes cluster with Elastic Agent](https://observability-docs_bk_4532.docs-preview.app.elstc.co/guide/en/serverless/current/observability-quickstarts-k8s-logs-metrics.html)

Some auto-generated images are also problematic.

### Resources

Use the width/height settings in the [docs readme](https://github.com/elastic/docs/blob/master/README.asciidoc#width-and-height)

### Which documentation set does this change impact?

Stateful and Serverless

### Feature differences

n/a

### What release is this request related to?

N/A

### Collaboration model

The documentation team

### Point of contact.

@alaudazzi