[ISSUE] add to getting-started documentation how to increase minikube resources if not starting for first time

[mattcallanan]

In https://expediadotcom.github.io/haystack/docs/about/getting_started.html, after the following instructions:

Start Minikube, optionally increasing its memory and/or CPUs if necessary:
minikube start --memory 8192 --cpus 4

Add the following:

NOTE: if minikube has been previously started without these resource parameters, you may need to convince it to forget it's previous settings. You can use one of the following 2 methods:

1. Stop minikube (minikube stop), manually change the memory and cpu settings in your Virtual Machine software, then restart minikube (minikube start)
2. Delete minikube (with minikube stop ; minikube delete) before re-running the above minikube start ... instruction

For more details, see: kubernetes/minikube#567 (comment)

[shreyaa-sharma]

We have to enhance the UI documentation for this. @keshavpeswani will get this done by end of the day.