Update README and example with server version

Author: kfischer-okarin

README.md

@@ -50,6 +50,7 @@ module ModelContextProtocol
     def index
       server = ModelContextProtocol::Server.new(
         name: "my_server",
+        version: "1.0.0",
         tools: [SomeTool, AnotherTool],
         prompts: [MyPrompt],
         server_context: { user_id: current_user.id },

examples/stdio_server.rb

@@ -54,6 +54,7 @@ def template(args, server_context:)
 # Set up the server
 server = MCP::Server.new(
   name: "example_server",
+  version: "1.0.0",
   tools: [ExampleTool],
   prompts: [ExamplePrompt],
   resources: [