feat: document two-step registration (#1694)

* feat: document two-step registration
* fix: add passkey console screenshot

Author: hperl

docs/identities/sign-in/_static/two-step-registration.png

@@ -0,0 +1,33 @@
+---
+id: two-step-registration
+title: Two-step registration
+sidebar_label: Two-step registration
+slug: two-step-registration
+---
+
+With a one-step registration, when you enable multiple authentication strategies (for example password, code via email, and
+passkey), the identity traits will be repeated for each authentication strategy.
+
+Compare this to a two-step registration: Now, the user is prompted for the identity traits in the first step, and asked to choose
+a credential method for authentication next. This results in a more stream-lined user experience.
+
+:::info
+
+Identity traits are data associated with an identity that can be modified by the user. The traits are configured through the
+identity schema.
+
+[Learn more about identity traits](../../kratos/manage-identities/managing-users-identities-metadata#traits)
+
+:::
+
+![Registration with two-step registration vs one-step registration](./_static/two-step-registration.png)
+
+To disable the legacy one-step registration, go to https://console.ory.sh/projects/current/authentication and switch off "Enable
+legacy one-step registration" or use the Ory CLI:
+
+```bash
+ory list projects # to get the project id
+
+ory patch project ${project_id} \
+  --replace '/services/identity/config/selfservice/flows/registration/enable_legacy_one_step=false'
+```

docs/identities/sign-in/two-step-registration.mdx

@@ -46,14 +46,19 @@ login. Here is a comparison of the two approaches:
 
 ### Configuration
 
-:::info
+By default, the passkey strategy is disabled. You can enable it in the Ory Console by going to
+[https://console.ory.sh/projects/current/passwordless](https://console.ory.sh/projects/current/passwordless) and toggling the
+switch for "Enable Passkey authentication".
 
-This feature is in preview. Please report any issues to [email protected] or contact us in the
-[Ory Community](https://slack.ory.sh/).
+```mdx-code-block
+<BrowserWindow url="https://console.ory.sh/projects/current/passwordless">
 
-:::
+![Passkey in Console](../_static/passkeys/console.png)
+
+</BrowserWindow>
+```
 
-By default, the passkey strategy is disabled. To start using the passkey strategy, apply this configuration:
+Alternatively, use the Ory CLI to enable the passkey strategy:
 
 ```mdx-code-block
 import CodeBlock from '@theme/CodeBlock'

docs/kratos/_static/passkeys/console.png

@@ -97,6 +97,7 @@ module.exports = {
             "identities/sign-in/check-session",
             "identities/sign-in/actions",
             "identities/sign-in/login-hint",
+            "identities/sign-in/two-step-registration",
           ],
         },
         {