chore: Fixed namespace doc for Crossplane Example

[stevenfollis]

Instruction to list pods in crossplane namespace does not work, as the namespace created through blueprint is crossplane-system.

What does this PR do?

This [minor] PR updates the Readme.md file to fix the specified namespace name to crossplane-system.

$ kubectl get pods -n crossplane
No resources found in crossplane namespace.

$ kubectl get pods -n crossplane-system
NAME                                             READY   STATUS    RESTARTS   AGE
aws-provider-f78664a342f1-b56dc7c4b-m2q49        1/1     Running   0          3m20s
crossplane-5696d784b8-26xps                      1/1     Running   0          5m57s
crossplane-rbac-manager-8466dfb7fc-4l8tr         1/1     Running   0          5m57s
jet-aws-provider-b42c59584ad8-6b4c7685dc-8bdj7   1/1     Running   0          3m41s

Motivation

• This fix should help future uses of the example be successful

More

• Yes, I have tested the PR using my local account setup (Provide any test evidence report under Additional Notes)
• Yes, I have added a new example under examples to support my PR
• Yes, I have created another PR for add-ons under add-ons repo (if applicable)
• Yes, I have updated the docs for this feature
• Yes, I ran pre-commit run -a with this PR

Note: Not all the PRs require a new example and/or doc page. In general:

• Use an existing example when possible to demonstrate a new addons usage
• A new docs page under docs/add-ons/* is required for new a new addon

For Moderators

• E2E Test successfully complete before merge?

Additional Notes

I stan EKS Blueprints ❤️

[bryantbiggs]

Thank you sir!

[askulkarni2]

Thanks for the PR!!