added comments

app/controllers/supporters_controller.rb

@@ -18,6 +18,6 @@ class SupportersController < ApplicationController
   private
 
   def supporter_form_params
-    params.require(:supporter).permit(:first_name, :last_name, :street, :zip, :email, :support, :age_category, :city)
+    params.require(:supporter).permit(:first_name, :last_name, :street, :zip, :email, :support, :age_category, :city, :comments)
   end
 end

app/models/supporter.rb

@@ -17,6 +17,7 @@ class Supporter
   field :support,      type: String # Indicates the type of support
   field :age_category, type: String
   field :coordinates,  type: Array
+  field :comments,     type: String
 
   validates :first_name,   presence: true
   validates :last_name,    presence: true

app/views/supporters/_form.slim

@@ -11,6 +11,7 @@ h1 = title t('.title_html')
       = f.input :email, placeholder: t('.placeholders.email')
       = f.input :support, as: :radio_buttons, collection: t('support_type'), label_method: :last, value_method: :first
       = f.input :age_category, as: :radio_buttons, collection: t('age_category'), label_method: :last, value_method: :first
+      = f.input :comments, as: :text
       .form-group
         = f.submit value: t('.submit'), class: 'btn btn-success'
       .form-group