describe metadata overview

Reviewed-by: Gode, Sebastian <sebastian.gode@t-systems.com>
Co-authored-by: tischrei <tino.schreiber@t-systems.com>
Co-committed-by: tischrei <tino.schreiber@t-systems.com>

otc_metadata/data/service_categories/README.md

@@ -0,0 +1,18 @@
+# 📁 service_categories/
+
+Contains the list of service category definitions. These categories help group services (e.g., "Application", "Database").
+
+## 🔧 Example: `compute.yaml`
+
+```yaml
+---
+name: compute
+title: Computing
+```
+
+## Parameter Reference
+
+| Field   | Type   | Description                           |
+| ------- | ------ | ------------------------------------- |
+| `name`  | string | Internal identifier for the category. |
+| `title` | string | Display name used in UIs.             |