Add helm example project

[pjaudiomv]

I have created a helm chart for deploying the proxy to Kubernetes and thought it may be useful for others to use.

as a minimal example to test locally you could use minikube

minikube start --memory=4192 --cpus=4 --kubernetes-version=v1.30.0
helm repo add email-oauth2-proxy  https://pjaudiomv.github.io/email-oauth2-proxy-helm
helm repo update
kubectl create namespace email-oauth2-proxy
helm install email-oauth2-proxy email-oauth2-proxy/email-oauth2-proxy -f values.yaml

example values.yaml

setupPod:
  enabled: true
config:
  DEBUG: true
  CACHE_STORE: /app/cache/credstore.config
configMap:
  enabled: true
  data: |
      [IMAP-2993]
      server_address = imap.gmail.com
      server_port = 993
      local_address = 0.0.0.0
    
      [[email protected]]
      permission_url = https://accounts.google.com/o/oauth2/auth
      redirect_uri = http://localhost/
      oauth2_scope = https://mail.google.com/
      token_url = https://oauth2.googleapis.com/token
      client_id = 167903-obfusicated-3hol.apps.googleusercontent.com
      client_secret = GOCSPX-Pet-rdummy-data-gPIOc

For my purposes, I get the proxy going in setup pod interactively and from there the proxy service pod uses the cache store persistent volume

[simonrob]

Thanks for the contribution!