Added mimimum version of Vault in the documentation

doc/ci/examples/authenticating-with-hashicorp-vault/index.md

@@ -22,8 +22,7 @@ This tutorial assumes you are familiar with GitLab CI/CD and Vault.
 To follow along, you must have:
 
 - An account on GitLab.
-- A running Vault server and access to it is required to configure authentication and create roles
-  and policies. For HashiCorp Vaults, this can be the Open Source or Enterprise version.
+- Access to a running Vault server (at least v1.2.0) to configure authentication and to create roles and policies. For HashiCorp Vaults, this can be the Open Source or Enterprise version.
 
 NOTE:
 You must replace the `vault.example.com` URL below with the URL of your Vault server, and `gitlab.example.com` with the URL of your GitLab instance.

doc/ci/secrets/index.md

@@ -53,6 +53,7 @@ and supports multiple secrets engines.
 
 To configure your Vault server:
 
+1. Ensure your Vault server is running on version 1.2.0 or higher.
 1. Enable the authentication method by running these commands. They provide your Vault
    server the [JSON Web Key Set](https://tools.ietf.org/html/rfc7517) (JWKS) endpoint for your GitLab instance, so Vault
    can fetch the public signing key and verify the JSON Web Token (JWT) when authenticating: