Rename methods to add auto links to HTML

The name `safe_html_with_links` was confusing and could make you think
it takes care of making the HTML safe. So I've renamed it in a way that
makes it a bit more intuitive that it expects its input to be already
sanitized.

I've changed `text_with_links` as well so now the two method names
complement each other.

app/views/milestones/_milestone.html.erb

@@ -25,7 +25,7 @@
     <%= image_tag(milestone.image_url(:large), { id: "image_#{milestone.id}", alt: milestone.image.title, class: "margin" }) if milestone.image.present? %>
 
     <p>
-      <%= text_with_links milestone.description %>
+      <%= sanitize_and_auto_link milestone.description %>
     </p>
 
     <% if milestone.documents.present? %>