add James Stevenson as website coordinator

(in addition to other updates)

Author: nlharris

_data/roles.yml

@@ -74,6 +74,11 @@
       orcid: 0000-0002-7356-1779
       status: support
       start: "0000-00-00"
+    - github: jsstevenson
+      name: James Stevenson
+      orcid: 0000-0002-2568-6163
+      status: lead
+      start: "2025-00-00"
 - name: OBO Slack Community Manager
   open: false
   commitment: 1-3 hours per month