consider symlink support

[codefromthecrypt]

Is your feature request related to a problem? Please describe.

currently, if you uncar something that has symlinks you won't get them

for example, springcloud/spring-cloud-kubernetes-discoveryserver:3.1.0 has symlinks in it

$ ls -al /cnb/process/web
lrwxrwxrwx 1 root root 23 Jan  1  1980 /cnb/process/web -> /cnb/lifecycle/launcher

Describe the solution you'd like

symlinks should be supported if the underlying OS does and they don't escape the relative directory

Describe alternatives you've considered

just not supporting them at all, but then it is confusing for example troubleshooting something like springcloud/spring-cloud-kubernetes-discoveryserver:3.1.0 where the entrypoint is a symlink