accounts: document SAML authentication
accounts: document SAML authentication

This closes #19

Signed-off-by: Rohit Yadav <0fa72ca37c4b5fa62675187ce32ea6c9f842fd52@apache.org>
Signed-off-by: Sebastien Goasguen <250735a416ca4fba2eb297c8d62b7a634570c133@gmail.com>

apache/cloudstack-docs-admin,lmrv/cloudstack-docs-admin,pdion891/cloudstack-docs-admin,lmrv/cloudstack-docs-admin,pdion891/cloudstack-docs-admin,unodba/cloudstack-docs-admin,unodba/cloudstack-docs-admin,pdion891/cloudstack-docs-admin,unodba/cloudstack-docs-admin,apache/cloudstack-docs-admin,lmrv/cloudstack-docs-admin,apache/cloudstack-docs-admin