Add widget feeds to homepage

Note there is some funkiness going on with class loadings
Had to create a `feed` and `widget_feed` table even though in this
first version the Widget::Feed includes only uses ActiveModel instead
of ActiveRecord, otherwise some specs failed

We’ll figure it out and clean up 😌

app/views/welcome/_feeds.html.erb

@@ -0,0 +1,16 @@
+<h1>Feeds</h1>
+
+<% @feeds.each do |feed| %>
+  
+  <div>
+    <strong>Most active <%= feed.kind %></strong>
+  </div>
+
+  <% feed.items.each do |item| %>    
+    <div class="<%= item.class.to_s.parameterize('_') %>">
+      <%= item.title %>
+    </div>
+    <br/>
+  <% end %>
+  
+<% end %>

app/views/welcome/index.html.erb

@@ -24,6 +24,7 @@
 </div>
 
 <%= render "header", header: @header %>
+<%= render "feeds" %>
 <%= render "cards" %>
 
 <% if feature?("user.recommendations") && (@recommended_debates.present? || @recommended_proposals.present?) %>