add softe configs to the umami config repo

Add preprocessing and training configs for soft electron to the official repo

• The configs are used originally for DL1re training with Umami tag 0.2-189-gfbf3ead
• recently updated to work with Umami tag 0.10-20-g9f11938 for evaluating
• should only serve as an example for settings specific to soft electrons. Please check the latest Umami documentation and config files for other settings.

related to the issue: ftag-docs#17 (closed)