Add Apollo MCP Server to mcp-registry (github#60)

* add apollo mcp server

* parameters should only include properties that are referenced in environment variables

Author: DaleSeo

servers/apollo-mcp-server/server.yaml

@@ -0,0 +1,32 @@
+name: apollo-mcp-server
+image: ghcr.io/apollographql/apollo-mcp-server
+type: server
+meta:
+  category: ai
+  tags:
+    - ai
+about:
+  title: Apollo MCP Server
+  description: Enable graph-based API orchestration with AI
+  icon: https://www.apollographql.com/favicon/android-icon-192x192.png
+source:
+  project: https://github.com/apollographql/apollo-mcp-server
+config:
+  description: Configure the connection to Apollo MCP Server
+  env:
+    - name: APOLLO_KEY
+      example: service:mygraph:1234567890
+      value: "{{apollo-mcp-server.apollo-key}}"
+    - name: APOLLO_GRAPH_REF
+      example: MyGraph@current
+      value: "{{apollo-mcp-server.apollo-graph-ref}}"
+  parameters:
+    type: object
+    properties:
+      apollo-key:
+        type: string
+      apollo-graph-ref:
+        type: string
+    required:
+      - apollo-key
+      - apollo-graph-ref