Dear,
this can be fixed easily:
1- in nginx.dockerfile add /bin/sh to those 2 lines:
RUN /bin/sh ./files/prebuild/write-version.sh
RUN /bin/sh ./files/prebuild/build-frontend.sh
Then replace the Windows EOL by linux EOLin all the files (Git wrongly configured to use CRLF instead of LF when writing the files)
br