Add information on pre-installing GitOps Catalog apps from the CLI

[fharper]

What type of suggestions?

Missing Information

What page is concerned?

https://kubefirst.konstruct.io/docs/civo/gitops-catalog

What version of the docs?

2.7+

What is the issue?

Add information on pre-installing GitOps Catalog apps from the CLI using the -install-catalog-apps flag.

Code of Conduct

• I agree to follow this project's Code of Conduct