Compare Radius with Klotho

[lakshmimsft]

What content needs to be created or modified?

There was a request on discord for a comparison of Radius with Klotho https://discord.com/channels/1113519723347456110/1113519723930468455/1260349574246301779

Describe the solution you'd like

Add documentation for comparison of Radius with Klotho

Where should the new material be placed?

FAQ section

The associated pull request from the Radius code repo, if applicable

Additional context

AB#12680