Add gr-oss schema

Author: pavlovic-ivan

.schemas/repository-config.gr-oss.schema.json

@@ -0,0 +1,30 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://raw.githubusercontent.com/G-Research/github-terraformer/refs/heads/main/.schemas/repository-config.gr-oss.schema.json",
+  "title": "Repository Configuration (GR-OSS)",
+  "allOf": [
+    {
+      "$ref": "repository-config.schema.json"
+    },
+    {
+      "properties": {
+        "custom_properties": {
+          "properties": {
+            "oss_lifecycle": {
+              "type": "string",
+              "enum": [
+                "published",
+                "active",
+                "contributing",
+                "maintained",
+                "evaluating",
+                "deprecated",
+                "archived"
+              ]
+            }
+          }
+        }
+      }
+    }
+  ]
+}