add logEncoding to helm chart's values.yaml

[bwagner5]

1. Issue, if available:
#1637

2. Description of changes:

• Add logEncoding to values.yaml so that users can configure between console and json logs

3. How was this change tested?

helm upgrade --install karpenter charts/karpenter --namespace karpenter \
		--set serviceAccount.annotations.eks\\.amazonaws\\.com/role-arn=arn:aws:iam::xxxxxxxxxx:role/eksctl-karpenter-demo-addon-iamserviceaccoun-Role1-1EYIC0TUBRWJV 
                --set clusterName=karpenter-demo 
                --set clusterEndpoint=https://xxxxxxxxxx.gr7.us-west-2.eks.amazonaws.com 
                --set logEncoding=json 
                --set aws.defaultInstanceProfile=KarpenterNodeInstanceProfile-karpenter-demo \
	        --set controller.image=xxxxxxxxxx.dkr.ecr.us-east-2.amazonaws.com/karpenter/controller@sha256:c1fae686e87356a5f49c6e8a8c2577eedc3af63575f37241b308544159deac79 \
		--set webhook.image=xxxxxxxxxx.dkr.ecr.us-east-2.amazonaws.com/karpenter/webhook@sha256:2a758ce4ed8e7488d2bbe19a82bdd3f7155ae2aed61e4f81d6aeac4bb30c21ce

4. Does this change impact docs?

• Yes, PR includes docs updates
• Yes, issue opened: link to issue
• No

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

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[tzneal]

Pulled it down, edited my values.yaml and it works:

karpenter-9959b9c49-ggqvm controller {"level":"DEBUG","time":"2022-04-08T16:16:59.899Z","logger":"controller.provisioning","message":"Discovered 402 EC2 instance types","commit":"cf9a194","provisioner":"default"}
karpenter-9959b9c49-ggqvm controller {"level":"DEBUG","time":"2022-04-08T16:17:00.059Z","logger":"controller.provisioning","message":"Discovered subnets: [subnet-01caedfa832765807 (us-west-2b) subnet-08b04a750cf84d65e (us-west-2a) subnet-0527a666024f87542 (us-west-2b) subnet-0c85abf88a452b4c5 (us-west-2c) subnet-0f102b1ea0880fa0d (us-west-2a) subnet-0c5e0a8bdec952b40 (us-west-2c)]","commit":"cf9a194","provisioner":"default"}
karpenter-9959b9c49-ggqvm controller {"level":"DEBUG","time":"2022-04-08T16:17:00.185Z","logger":"controller.provisioning","message":"Discovered EC2 instance types zonal offerings","commit":"cf9a194","provisioner":"default"}
karpenter-9959b9c49-ggqvm controller {"level":"INFO","time":"2022-04-08T16:17:00.189Z","logger":"controller.provisioning","message":"Waiting for unschedulable pods","commit":"cf9a194","provisioner":"default"}

LGTM