Add provider specific SAML documentation

[deepakprabhakara]

Is your proposal related to a problem?

Test more SAML providers and add instructions for each provider.

Describe the solution you'd like

Okta, Google and Auth0 have been tested and supported so far. Test the following popular providers and document specific instructions - OneLogin, Duo, Azure, CyberArk, ADFS, JumpCloud, Shibboleth (not an exhaustive list).