Replace expired oxAuth key - doc

[mzico]

• Here is the doc on how to generate new oxAuth key and replace expired one: https://github.com/GluuFederation/support-docs/blob/master/troubleshooting/oxAuth/oxAuth_key_generation.md

• Where to place?

I think we can create 'three' bullets under Operation Guide --> Replacing Expired JKS Files

• Section one: "Renew expired SCIM JKS key"
• Section two: "Renew expired oxAuth key"
• Section three: "Renew expired Passport key" ( Renew Passport keys: https://github.com/GluuFederation/support-docs/blob/e4446b93058408c2ca22e355b2afe1c7ca1f6ffd/howto/ssl/Renew_passport_jks.md )

[yuriyz]

In docs we should recommend to use python script for re-generation instead of manual steps. See GluuFederation/community-edition-setup#641