ga4gh#79 issue : Created schema.json and schema.yaml

Schema File:

Add the "accessions" attribute in the schema definition (e.g., in schema.json, schema.yaml, or relevant model files).
Validation Files (if applicable):

Implement or update validation logic for the new attribute.

Signed off by : `Srinjoy sen Chowdhury srinjoysen123@gmail.com`

Author: AllMightLegend

schemas/schema.json

@@ -0,0 +1,20 @@
+{
+    "type": "object",
+    "properties": {
+      "id": {
+        "type": "string"
+      },
+      "name": {
+        "type": "string"
+      },
+      "accessions": {
+        "type": "array",
+        "items": {
+          "type": "string",
+          "description": "An array of accession identifiers, each prefixed with the authority (e.g., NCBI:XXXX, ENA:YYYY)"
+        }
+      }
+    },
+    "required": ["id", "accessions"]
+  }
+  

schemas/schema.yaml

@@ -0,0 +1,14 @@
+type: object
+properties:
+  id:
+    type: string
+  name:
+    type: string
+  accessions:
+    type: array
+    items:
+      type: string
+      description: "An array of accession identifiers, each prefixed with the authority (e.g., NCBI:XXXX, ENA:YYYY)"
+required:
+  - id
+  - accessions