Minor fixes

Fixed subnavigation active links and button to create new proposal.

app/helpers/tags_helper.rb

@@ -8,6 +8,8 @@ module TagsHelper
       proposals_path(search: tag_name)
     when 'budget/investment'
       budget_investments_path(@budget, search: tag_name)
+    when 'legislation/proposal'
+      legislation_process_proposals_path(@process, search: tag_name)
     else
       '#'
     end

app/views/legislation/processes/proposals.html.erb

@@ -20,9 +20,7 @@
       </div>
 
       <div class="small-12 medium-3 column">
-        <div class="callout success">
-          <p><%= t('.participate') %></p>
-        </div>
+        <p><%= link_to t("proposals.index.start_proposal"), new_legislation_process_proposal_path(@process), class: 'button expanded' %></p>
       </div>
     </div>
   </div>

app/views/shared/_subnavigation.html.erb

@@ -12,7 +12,7 @@
     <li>
       <%= layout_menu_link_to t("layouts.header.proposals"),
                                 proposals_path,
-                                controller_name == 'proposals',
+                                controller_name == 'proposals' && !controller.class.parent == Legislation,
                                 accesskey: "2",
                                 title: t("shared.go_to_page") + t("layouts.header.proposals") %>
     </li>