fix next steps message formatting

Author: fdiblen

copier/messages.yml

@@ -31,11 +31,11 @@ _message_after_copy: |
 
                 git push --set-upstream origin main
 
-          {% if AddDevDoc %}
+          {% if AddDevDoc -%}
             - Project development documentation
 
-                The [README.dev.md](README.dev.md) contains developer documentation
-          {%- endif-%}
+                The README.dev.md contains developer documentation
+          {%- endif %}
 
             - Project layout explained