Added WRITABLE_PATH to Windows start-wekan.bat .

Thanks to BabyFnord and xet7 !

Related https://github.com/wekan/wekan/pull/4405

start-wekan.bat

@@ -11,6 +11,11 @@ SET ROOT_URL=http://localhost
 SET PORT=80
 SET MONGO_URL=mongodb://127.0.0.1:27017/wekan
 
+REM Writable path for temporary saving attachments during migration to Meteor-Files
+REM Create directory wekan-uploads
+MD wekan-uploads
+SET WRITABLE_PATH=wekan-uploads
+
 REM # https://github.com/wekan/wekan/wiki/Troubleshooting-Mail
 REM SET MAIL_URL=smtps://username:password@email-smtp.eu-west-1.amazonaws.com:587/
 REM SET MAIL_FROM="Wekan Boards <info@example.com>"