speakers prop is image_src not img_src

_data/speakers.yml

@@ -34,7 +34,7 @@
   institution: JSTOR Labs
   position-title: Software Engineering Manager
   bio: "Matthew is a software engineer and manager who leads the technical team for JSTOR Labs. He's originally an art historian and digital humanist and interested in all things cultural heritage data."
-  img_src: /assets/img/speakers/matthew-lincoln.jpeg
+  image_src: /assets/img/speakers/matthew-lincoln.jpeg
   image_alt: "A man with black thick-rimmed glasses and short hair"
   keynote: false
 - id: "olivia-wikle"