use heredoc to cleanup code example

Author: jcat4

README.md

@@ -640,9 +640,11 @@ client = MCP::Client.new(transport: http_transport)
 # List available tools
 tools = client.tools
 tools.each do |tool|
-  puts "Tool: #{tool.name}"
-  puts "Description: #{tool.description}"
-  puts "Input Schema: #{tool.input_schema}"
+  puts <<~TOOL_INFORMATION
+    Tool: #{tool.name}
+    Description: #{tool.description}
+    Input Schema: #{tool.input_schema}
+  TOOL_INFORMATION
 end
 
 # Call a specific tool