docs: move Adam & Toby to registry emeritus; add Pree as collaborator (modelcontextprotocol#2825)

* docs: move Adam and Toby to registry emeritus

Removes Adam Jones and Toby Padilla from the active Registry maintainers
list and records them under a new Registry Emeritus subsection. Adam
remains an active MCPB maintainer (unchanged).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

* Update MAINTAINERS.md

---------

Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>

Author: tadasant

MAINTAINERS.md

@@ -121,12 +121,15 @@ This document lists current maintainers in the Model Context Protocol project.
 
 ### Registry
 
-- [Toby Padilla](https://github.com/toby)
 - [Tadas Antanavicius](https://github.com/tadasant)
-- [Adam Jones](https://github.com/domdomegg)
 - [Radoslav (Rado) Dimitrov](https://github.com/rdimitrov)
 - [Bob Dickinson](https://github.com/BobDickinson)
 
+#### Registry Emeritus
+
+- [Adam Jones](https://github.com/domdomegg)
+- [Toby Padilla](https://github.com/toby)
+
 ### MCPB (Model Context Protocol Bundle)
 
 - [Alexander Sklar](https://github.com/asklar)