Changing var to let in JS curriculum

<%= @topic_view.topic.title %>
<%= @topic_view.topic.average_rating %> <%= @topic_view.topic.posts.count { |p| !!p.custom_fields['rating'] } %>

Hey guy, if you give me an access I think I can change all the VARs to LETs in JS section.
Or we can form a group 2-3 persons to update these scripts.

That would need to be discussed in an issue first. We don’t necessarily want to change all var to let or const. We have a whole section which covers that syntax.