Fix an error when using bin/console

Follow-up to modelcontextprotocol#24.

This PR fixes the following error when using `bin/console`:

```console
$ bin/console
/Users/koic/.rbenv/versions/3.4.4/lib/ruby/3.4.0/bundled_gems.rb:82:
in 'Kernel.require': cannot load such file -- model_context_protocol (LoadError)
from /Users/koic/.rbenv/versions/3.4.4/lib/ruby/3.4.0/bundled_gems.rb:82:
in 'block (2 levels) in Kernel#replace_require'
        from bin/console:5:in '<main>'
```

Author: koic

bin/console

@@ -2,7 +2,7 @@
 # frozen_string_literal: true
 
 require "bundler/setup"
-require "model_context_protocol"
+require "mcp"
 
 # You can add fixtures and/or initialization code here to make experimenting
 # with your gem easier. You can also use a different console, if you like.