* Replaces saml-okta-setup.png

* Added a table of the attributes

* Making the SAML guide more clear

I added links to the underlying documentation (I found a OneLogin guide eventually). I think that this is the best way to handle it so that we don't have to update our documentation if the underlying SAML providers make a change - hopefully, they will maintain their own docs. I also added tables to help make the different field descriptions more clear.

https://github.com/metabase/metabase/pull/8869

this has been broken for a while =(

[ci skip]