Update images: Added new model screenshots

PR to update images for bamf_nnunet_mr_liver model web page

/test

sample:
  idc_version: "Data Release 5.0 May 29, 2020"
  data:
  - SeriesInstanceUID: 1.3.6.1.4.1.14519.5.2.1.3344.4008.295183335434779171346930899761
    aws_url: s3://idc-open-data/ff8819d4-69a4-4c73-bcb2-23b5d23efdd0/*
    path: dicom

reference:
  url: https://drive.google.com/file/d/1rqKPxaRax_qGmnYqD2IwF8dgsknOpjjl/view?usp=sharing

ct_liver.zip

MHubAI / models

Update images: Added new model screenshots #88