[Docs] Remove redundant parentheses

In Ruby, it is generally not customary to add parentheses to methods without arguments.
This PR removes such redundant parentheses from the documentation.

This PR removes redundant parentheses.
In Ruby, it is generally not customary to add parentheses to methods without arguments.

Author: koic

README.md

@@ -108,9 +108,9 @@ The server supports sending notifications to clients when lists of tools, prompt
 
 The server provides three notification methods:
 
-- `notify_tools_list_changed()` - Send a notification when the tools list changes
-- `notify_prompts_list_changed()` - Send a notification when the prompts list changes
-- `notify_resources_list_changed()` - Send a notification when the resources list changes
+- `notify_tools_list_changed` - Send a notification when the tools list changes
+- `notify_prompts_list_changed` - Send a notification when the prompts list changes
+- `notify_resources_list_changed` - Send a notification when the resources list changes
 
 #### Notification Format
 
@@ -134,7 +134,7 @@ server.transport = transport
 
 # When tools change, notify clients
 server.define_tool(name: "new_tool") { |**args| { result: "ok" } }
-server.notify_tools_list_changed()
+server.notify_tools_list_changed
 ```
 
 ### Unsupported Features ( to be implemented in future versions )