Add search method to legislation processes

This way we'll be able to search processes in the SDG Management
section.

app/models/legislation/process.rb

@@ -5,6 +5,7 @@ class Legislation::Process < ApplicationRecord
   include Imageable
   include Documentable
   include SDG::Relatable
+  include Searchable
 
   acts_as_paranoid column: :hidden_at
   acts_as_taggable_on :customs
@@ -123,6 +124,22 @@ class Legislation::Process < ApplicationRecord
     end
   end
 
+  def searchable_translations_definitions
+    {
+      title       => "A",
+      summary     => "C",
+      description => "D"
+    }
+  end
+
+  def searchable_values
+    searchable_globalized_values
+  end
+
+  def self.search(terms)
+    pg_search(terms)
+  end
+
   private
 
     def valid_date_ranges