Merge branch 'update-fluxcd-install-note' into 'master'

Update flux install command to not pipe directly to a privileged shell

Minor doc update.  Example of why `curl | bash` is not a good idea:

https://www.idontplaydarts.com/2016/04/detecting-curl-pipe-bash-server-side/

See merge request platform-one/big-bang/umbrella!97

docs/2_getting_started.md

@@ -14,7 +14,7 @@ Table of Contents
 
 - Admin tools
   - [Docker](https://docs.docker.com/engine/install/)
-  - [Flux CLI](https://toolkit.fluxcd.io/get-started/#install-the-flux-cli):     `curl -s https://toolkit.fluxcd.io/install.sh | sudo bash`
+  - [Flux CLI](https://toolkit.fluxcd.io/get-started/#install-the-flux-cli):     `brew install fluxcd/tap/flux`
   - [Git](https://git-scm.com/download/)
   - [Helm](https://helm.sh/docs/intro/install/)
   - [Kubectl](https://kubernetes.io/docs/tasks/tools/install-kubectl/)