Improve UX for Cloudflow CLI installation documentation

[longmuir]

This page: https://cloudflow.io/docs/current/get-started/prepare-development-environment.html

Currently, you have to hunt for several commands(download file, move, uncompress, set permissions, etc) to download and install the Cloudflow kubectl CLI. This could be made much smoother for users by providing a few commands they can copy paste depending on their environment.

Examples for other CLIs: https://kubernetes.io/docs/tasks/tools/install-kubectl/ https://docs.aws.amazon.com/cli/latest/userguide/install-cliv2.html

The net impact for users is that something that could be done in a few seconds takes several minutes. A better guide here could get users into Cloudflow faster.