add credits list

README.md

@@ -87,4 +87,10 @@ After our rate of change slows a bit, we will make beta builds available here (w
 
 # Development
 
-We'd love to have you join us on this merry little project.  Please see our [development documents](./docs/software/sw-design.md) and join us on the gitter chat above.
+We'd love to have you join us on this merry little project.  Please see our [development documents](./docs/software/sw-design.md) and join us on the gitter chat above.
+
+# Credits
+
+This project is run by volunteers.  Past contributors include:
+* @claesg: Various documentation fixes and 3D print enclosures
+* @girtsf: So far our CI system, but soon lots of device improvements