fix link to setup instructions

Author: tobyhodges

learners/setup.md

@@ -6,7 +6,7 @@ This lesson is designed to be taught in conjunction with other lessons
 in the [Data Carpentry Geospatial workshop](http://www.datacarpentry.org/geospatial-workshop/).
 For information about required software, and to access the datasets used
 in this lesson, see the
-[setup instructions](https://datacarpentry.org/geospatial-workshop/setup.html)
+[setup instructions](https://datacarpentry.org/geospatial-workshop/#setup)
 on the workshop homepage.