Include usage information for the oauth2-proxy field 'cookieSecret' (#…

…1316)

chart/kubeapps/values.yaml

@@ -491,7 +491,13 @@ authProxy:
   provider:
   clientID:
   clientSecret:
+  ## cookieSecret is used by oauth2-proxy to encrypt any credentials so that it requires
+  ## no storage. Note that it must be a particular number of bytes. Recommend using the
+  ## following to generate a cookieSecret as per the oauth2 configuration documentation
+  ## at https://pusher.github.io/oauth2_proxy/configuration :
+  ## python -c 'import os,base64; print base64.urlsafe_b64encode(os.urandom(16))'
   cookieSecret:
+  ## Use "example.com" to restrict logins to emails from example.com
   emailDomain: "*"
   ## Additional flags for oauth2-proxy
   ##