fix: typo in anchor text to OAuth 2.0 concept page (#861)

Author: David-Wobrock

docs/welcome.mdx

@@ -125,7 +125,7 @@ Don't want to deal with Docker, Kubernetes, and securing your API?
 **Read our in-depth concepts documentation**
 
 - [Identity and User Management (Ory Kratos)](https://www.ory.sh/docs/kratos/concepts/index)
-- [OAuth.20 & OpenIDConnect (Ory Hydra)](https://www.ory.sh/hydra/docs/concepts/oauth2)
+- [OAuth 2.0 & OpenIDConnect (Ory Hydra)](https://www.ory.sh/hydra/docs/concepts/oauth2)
 - [Authorization and Permission Server (Ory Keto)](https://www.ory.sh/docs/keto/concepts/relation-tuples/)
 - [Zero Trust Networking (Ory Oathkeeper)](https://www.ory.sh/oathkeeper/docs/)