Add survey links.

index.md

@@ -314,8 +314,8 @@ in `_config.yml` or, if this workshop is teaching a lesson in the Incubator,
 change the value of `carpentry` to `incubator`.
 </div>
 {% else %}
-<!-- <p><a href="{{ site.pre_survey }}{{ site.github.project_title }}">Pre-workshop Survey</a></p>
-<p><a href="{{ site.post_survey }}{{ site.github.project_title }}">Post-workshop Survey</a></p> -->
+<p><a href="{{ site.pre_survey }}{{ site.github.project_title }}">Pre-workshop Survey</a></p>
+<p><a href="{{ site.post_survey }}{{ site.github.project_title }}">Post-workshop Survey</a></p>
 {% endif %}
 
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