Easy doc improvement - give basic example of how to login to GUI

I like the approach over pointing to upstream docs, but we should at least have some basic level of documentation. I noticed the docs didn't have a basic how to login.

I deployed a default install of BB and it prompted me for token login. I think that's something new users would struggle with.

This might be a decent example that could be added to docs

export KIALI_SECRET=$(kubectl get secret -n=kiali | grep kiali-service-account-token | awk '{print $1}')
export KIALI_TOKEN=$(kubectl get secret $KIALI_SECRET -n=kiali --template={{.data.token}}  | base64 --decode )
echo $KIALI_TOKEN

Then just copy paste the $KIALI_TOKEN into the token based login prompt.