Fix (unrelated) broken links to the MCP spec

Author: jeffhandley

README.md

@@ -24,7 +24,7 @@ The Model Context Protocol (MCP) is an open protocol that standardizes how appli
 For more information about MCP:
 
 - [Official Documentation](https://modelcontextprotocol.io/)
-- [Protocol Specification](https://spec.modelcontextprotocol.io/)
+- [Protocol Specification](https://modelcontextprotocol.io/specification/)
 - [GitHub Organization](https://github.com/modelcontextprotocol)
 
 ## Installation

docs/index.md

@@ -13,7 +13,7 @@ The Model Context Protocol (MCP) is an open protocol that standardizes how appli
 For more information about MCP:
 
 - [Official Documentation](https://modelcontextprotocol.io/)
-- [Protocol Specification](https://spec.modelcontextprotocol.io/)
+- [Protocol Specification](https://modelcontextprotocol.io/specification/)
 - [GitHub Organization](https://github.com/modelcontextprotocol)
 
 For how-to guides, tutorials, and additional guidance, refer to the [official MCP documentation](https://modelcontextprotocol.io/).

samples/FileBasedMcpServer/README.md

@@ -61,4 +61,4 @@ echo '{"jsonrpc":"2.0","id":1,"method":"initialize","params":{"protocolVersion":
 
 - [File-Based Programs Tutorial](https://learn.microsoft.com/en-us/dotnet/csharp/fundamentals/tutorials/file-based-programs)
 - [C# Preprocessor Directives for File-Based Apps](https://learn.microsoft.com/en-us/dotnet/csharp/language-reference/preprocessor-directives#file-based-apps)
-- [Model Context Protocol Specification](https://spec.modelcontextprotocol.io/)
+- [Model Context Protocol Specification](https://modelcontextprotocol.io/specification/)

src/ModelContextProtocol.AspNetCore/README.md

@@ -14,7 +14,7 @@ The Model Context Protocol (MCP) is an open protocol that standardizes how appli
 For more information about MCP:
 
 - [Official Documentation](https://modelcontextprotocol.io/)
-- [Protocol Specification](https://spec.modelcontextprotocol.io/)
+- [Protocol Specification](https://modelcontextprotocol.io/specification/)
 - [GitHub Organization](https://github.com/modelcontextprotocol)
 
 ## Installation

src/ModelContextProtocol.Core/README.md

@@ -14,7 +14,7 @@ The Model Context Protocol (MCP) is an open protocol that standardizes how appli
 For more information about MCP:
 
 - [Official Documentation](https://modelcontextprotocol.io/)
-- [Protocol Specification](https://spec.modelcontextprotocol.io/)
+- [Protocol Specification](https://modelcontextprotocol.io/specification/)
 - [GitHub Organization](https://github.com/modelcontextprotocol)
 
 ## Installation