Add singlestore MCP server docker image (github#31)

* Add singlestore MCP server docker image

* fix singlestore server.yml

Author: Rodriguespn

servers/singlestore/server.yaml

@@ -0,0 +1,18 @@
+name: singlestore
+image: mcp/singlestore
+type: server
+meta:
+  category: database
+  tags:
+    - singlestore
+    - database
+about:
+  title: Singlestore
+  icon: https://avatars.githubusercontent.com/u/79943160?v=4
+source:
+  project: https://github.com/singlestore-labs/mcp-server-singlestore
+config:
+  secrets:
+    - name: singlestore.mcp_api_key
+      env: MCP_API_KEY
+      example: <MCP_API_KEY>