Resolve "Integrate Vault Package with SSO/OIDC"

Package Merge Request

Package Changes

Add documentation for Vault SSO integration with Keycloak.
Also add Vault client to keycloak dev baby-yoda realm config

Package MR

https://repo1.dso.mil/platform-one/big-bang/apps/sandbox/vault/-/merge_requests/36
https://repo1.dso.mil/platform-one/big-bang/apps/sandbox/vault/-/merge_requests/37
https://repo1.dso.mil/platform-one/big-bang/apps/security-tools/keycloak/-/merge_requests/59

For Issue

Closes #931 (closed)