Internal Release v0.1.1

- implement `Prompt`
- adjust Tool approach
- update readme for tool calling
- document usage of `Prompt`

lib/model_context_protocol/json_rpc/response.rb

@@ -0,0 +1,29 @@
+# frozen_string_literal: true
+
+module ModelContextProtocol
+  module JsonRPC
+    class Response
+      attr_reader :version, :result, :error, :id
+
+      def initialize(result: nil, error: nil, id: nil)
+        @version = VERSION
+        @result = result
+        @error = error
+        @id = id
+
+        validate!
+      end
+
+      def to_h
+        { id:, result:, jsonrpc: @version, error: @error&.to_h }.compact
+      end
+
+      private
+
+      def validate!
+        raise InvalidResponse, "Result and error cannot both be present" if @result && @error
+        raise InvalidResponse, "Either result or error must be present" if @result.nil? && @error.nil?
+      end
+    end
+  end
+end