mcp-rb MCP Server

From the README

# MCP-RB

A lightweight Ruby framework for implementing MCP (Model Context Protocol) servers with a Sinatra-like DSL.

## Installation

Add this line to your application's Gemfile:

```ruby
gem 'mcp-rb'
```

## Usage

Here's a simple example of how to create an MCP server:

```ruby
require 'mcp'

name "hello-world"

version "1.0.0"

# Define a resource
resource "hello://world" do
  name "Hello World"
  description "A simple hello world message"
  call { "Hello, World!" }
end

# Define a resource template
resource_template "hello://{user_name}" do
  name "Hello User"
  description "A simple hello user message"
  call { |args| "Hello, #{args[:user_name]}!" }
end

# Define a tool
tool "greet" do
  description "Greet someone by name"
  argument :name, String, required: true, description: "Name to greet"
  call do |args|
    "Hello, #{args[:name]}!"
  end
end

# Define a tool with nested arguments
tool "greet_full_name" do
  description "Greet someone by their full name"
  argument :person,