erp5_hal_json_style: do not use "Portal Type" in interface

As this term isn't explanatory for users

bt5/erp5_hal_json_style/SkinTemplateItem/portal_skins/erp5_hal_json_style/Base_viewNewContentDialog/your_portal_type.xml

@@ -245,7 +245,7 @@
                 </item>
                 <item>
                     <key> <string>title</string> </key>
-                    <value> <string>Portal Type</string> </value>
+                    <value> <string>Document Type</string> </value>
                 </item>
                 <item>
                     <key> <string>unicode</string> </key>