symbol_attribute_type.md moved to Attributes folder

Author: julitafalcondusza

docs/pim/symbol_attribute_type.md renamed to docs/pim/attributes/symbol_attribute_type.md

@@ -346,6 +346,7 @@ nav:
         - Products: pim/products.md
         - Attributes:
             - Date and Time attribute: pim/attributes/date_and_time.md
+            - Symbol attribute type: pim/attributes/symbol_attribute_type.md
         - Product API: pim/product_api.md
         - Catalogs: pim/catalogs.md
         - Catalog API: pim/catalog_api.md
@@ -360,7 +361,6 @@ nav:
             - Create custom name schema: pim/create_custom_name_schema_strategy.md
         - Use symbol attribute type: pim/symbol_attribute_type.md
         - Add remote PIM support: pim/add_remote_pim_support.md
-        - Use symbol attribute type: pim/symbol_attribute_type.md
     - Commerce:
         - Commerce: commerce/commerce.md
         - Cart: