docs: scim v2 interface (#9246)

# Which Problems Are Solved
- Lack of documentation for the SCIM v2 interface

# How the Problems Are Solved
- Introduced a new documentation page detailing the SCIM v2 interface

# Additional Context
Part of #8140

---------

Co-authored-by: Fabienne Bühler <fabienne@zitadel.com>

docs/sidebars.js

@@ -159,6 +159,7 @@ module.exports = {
             "guides/manage/user/reg-create-user",
             "guides/manage/customize/user-metadata",
             "guides/manage/customize/user-schema",
+            "guides/manage/user/scim2",
           ],
         },
         "guides/manage/terraform-provider",
@@ -837,6 +838,14 @@ module.exports = {
         },
       ],
     },
+    {
+      type: "category",
+      label: "Provision Users",
+      collapsed: true,
+      items: [
+          'apis/scim2'
+      ],
+    },
     {
       type: "category",
       label: "Actions",