Show tips when implementing an exercise

app/views/tips/_collapsed_card.html.slim

@@ -0,0 +1,24 @@
+- tip = exercise_tip.tip
+.card.mb-2
+  .card-header.p-2 id="tip-heading-#{exercise_tip.id}" role="tab"
+    .card-title.mb-0
+      a.collapsed aria-controls="tip-collapse-#{exercise_tip.id}" aria-expanded="false" data-parent="#tips" data-toggle="collapse" href="#tip-collapse-#{exercise_tip.id}"
+        .clearfix role="button"
+          i.fa aria-hidden="true"
+          span
+            = t('activerecord.models.tip.one')
+            =< exercise_tip.rank
+            = ": #{tip.title}" if tip.title?
+  .card.card-collapse.collapse id="tip-collapse-#{exercise_tip.id}" aria-labelledby="tip-heading-#{exercise_tip.id}" role="tabpanel"
+    .card-body.p-3
+      h5
+        = t('exercises.implement.tips.description')
+      = tip.description
+      - if tip.example?
+        h5.mt-2
+          = t('exercises.implement.tips.example')
+        pre
+          code.mh-100 class="language-#{tip.file_type.editor_mode.gsub("ace/mode/", "")}"
+            = tip.example
+      .mb-4
+      = render(partial: 'tips/collapsed_card', collection: exercise_tip.children, as: :exercise_tip)