feat(scf): Add STACKIT Cloud Foundry (#991)

* onboard STACKIT Cloud Foundry resources/datasource

docs/data-sources/scf_platform.md

@@ -0,0 +1,40 @@
+---
+# generated by https://github.com/hashicorp/terraform-plugin-docs
+page_title: "stackit_scf_platform Data Source - stackit"
+subcategory: ""
+description: |-
+  STACKIT Cloud Foundry Platform datasource schema.
+---
+
+# stackit_scf_platform (Data Source)
+
+STACKIT Cloud Foundry Platform datasource schema.
+
+## Example Usage
+
+```terraform
+data "stackit_scf_platform" "example" {
+  project_id  = "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
+  platform_id = "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
+}
+```
+
+<!-- schema generated by tfplugindocs -->
+## Schema
+
+### Required
+
+- `platform_id` (String) The unique id of the platform
+- `project_id` (String) The ID of the project associated with the platform
+
+### Optional
+
+- `region` (String) The region where the platform is located. If not defined, the provider region is used
+
+### Read-Only
+
+- `api_url` (String) The CF API Url of the platform
+- `console_url` (String) The Stratos URL of the platform
+- `display_name` (String) The name of the platform
+- `id` (String) Terraform's internal resource ID, structured as "`project_id`,`region`,`platform_id`".
+- `system_id` (String) The ID of the platform System