added Matthew Disimone to people data

Author: mdisi2

_data/people.yml

@@ -225,7 +225,7 @@
       name: LinkedIn
 
 - name: Matthew Disimone
-  pic: /img/people/disimonem.jpg
+  pic: /img/people/disimonem.png
   dates: 2024-Present
   role: Undergraduate Research Assistant
   description: 'Matthew Disimone is an undergraduate in NPRE and is interested in modeling neutron transport in advanced reactors.'