Add created_by to invoice and show it

app/views/finance/invoices/_form.html.haml

@@ -7,6 +7,11 @@
   - if @invoice.order
     %p= t('finance.invoices.linked', what_link: link_to(t('finance.invoices.linked_order'), new_finance_order_path(order_id: @invoice.order.id))).html_safe
 
+  - if @invoice.created_at
+    = f.input :created_at do
+      = format_time(@invoice.created_at)
+    = f.input :created_by do
+      = show_user(@invoice.created_by)
   = f.association :supplier, hint: false
   = f.input :number
   = f.input :date, as: :date_picker

app/views/finance/invoices/show.html.haml

@@ -1,5 +1,11 @@
 - title t('.title', number: @invoice.number)
 
+%p
+  %b= heading_helper(Invoice, :created_at) + ':'
+  = format_time(@invoice.created_at)
+%p
+  %b= heading_helper(Invoice, :created_by) + ':'
+  = show_user(@invoice.created_by)
 %p
   %b= heading_helper(Invoice, :supplier) + ':'
   = @invoice.supplier.name