Add guide to create a proposal or investment

During a Participatory Budget, some users are getting confused and
creating a proposal instead of a budget investment. This intermediate
page should help them create investments

Adding a feature flag just in case other forks don’t need this feature
and setting seeds and dev_seeds for appropriate initial setup

app/helpers/guides_helper.rb

@@ -0,0 +1,19 @@
+module GuidesHelper
+
+  def new_proposal_guide
+    if feature?("guides")
+      new_guide_path
+    else
+      new_proposal_path
+    end
+  end
+
+  def new_budget_investment_guide
+    if feature?("guides")
+      new_guide_path
+    else
+      new_budget_investment_path(current_budget)
+    end
+  end
+
+end