Datree validation plugin mentioned in docs no longer works

[corneliusroemer]

The docs currently use datree as example for validation.

The example no longer seems to work, maybe because datree has gone out of business. It would be good if the example was removed or replaced with a validation plugin that works (unless it still works and I'm doing something wrong)

cdk8s/docs/cli/synth.md

Lines 38 to 90 in 8524e84

	```yaml
	language: typescript
	app: ts-node main.ts
	validations:
	- package: '@datreeio/datree-cdk8s'
	class: DatreeValidation
	version: 1.3.4
	```
	With this configuration, `cdk8s` will dynamically install the `@datreeio/datree-cdk8s` package from NPM during
	synthesis, and produce a violation report. For example:
	```console
	Validation Report (@datreeio/[email protected])
	------------------------------------------------
	(Summary)
	╔═══════════╤════════════════════════╗
	║ Status │ failure ║
	╟───────────┼────────────────────────╢
	║ Plugin │ @datreeio/datree-cdk8s ║
	╟───────────┼────────────────────────╢
	║ Version │ 1.3.4 ║
	╟───────────┼────────────────────────╢
	║ Customize │ https://app.datree.io ║
	║ policy │ ║
	╚═══════════╧════════════════════════╝
	(Violations)
	Ensure each container image has a pinned (tag) version (2 occurrences)
	Occurrences:
	- Construct Path: cdk8s-app/Web/Resource
	- Manifest Path: ./dist/cdk8s-app.k8s.yaml
	- Resource Name: cdk8s-app-web-c825557e
	- Locations:
	> spec/template/spec/containers/0/image (line: 31:18)
	- Construct Path: cdk8s-app/Cache/Resource
	- Manifest Path: ./dist/cdk8s-app.k8s.yaml
	- Resource Name: cdk8s-app-cache-c8fee821
	- Locations:
	> spec/template/spec/containers/0/image (line: 112:18)
	Recommendation: Incorrect value for key `image` - specify an image version to avoid unpleasant "version surprises" in the future
	How to fix: https://hub.datree.io/ensure-image-pinned-version
	Validation failed. See above reports for details
	```