meta: move mmarchini to emeritus

Ref: nodejs/node#42750

README.md

@@ -84,7 +84,6 @@ This list should be reviewed and pruned annually (at minimum). The calendar has
 - [@joesepi](https://github.com/joesepi) - **Joe Sepi**
 - [@mcollina](https://github.com/mcollina) - **Matteo Collina**
 - [@mhdawson](https://github.com/mhdawson) - **Michael Dawson**
-- [@mmarchini](https://github.com/mmarchini) - **Mary Marchini**
 - [@MylesBorins](https://github.com/MylesBorins) - **Myles Borins**
 - [@ryanmurakami](https://github.com/ryanmurakami) - **Ryan Lewis**
 - [@trott](https://github.com/trott) - **Rich Trott**
@@ -97,6 +96,7 @@ This is a list of former maintainers of the Node.js Community Calendar. If these
 - [@bamieh](https://github.com/bamieh) - **Ahmad Bamieh**
 - [@dshaw](https://github.com/dshaw) - **Dan Shaw**
 - [@maddhruv](https://github.com/maddhruv) - **Dhruv Jain**
+- [@mmarchini](https://github.com/mmarchini) - **Mary Marchini**
 - [@gibfahn](https://github.com/gibfahn) - **Gibson Fahnestock**
 - [@hackygolucky](https://github.com/hackygolucky) - **Tracy Hinds**
 - [@williamkapke](https://github.com/williamkapke) - **William Kapke**