Document know shortcommings

Better documentation for known issues:

- `sys.prefix` vs `sys.base_prefix`
- harcoded interpreter path for **shebang** breaks some scripts (e.g snakemake)
- bin <-> _bin switch requires top level mount which means that some test run under an installation directory like `/appl` which is not mounted fails, but this is ok. As the program is not going to be run when in `/appl, fix is to mount `/appl` but this has not been done as to avoid calling broken installations in isolated environments
- Interacting with poetry does not seem to work, needs more testing.
- Unclear if venv installation behavior with adding new jupyter kernels is a bug