Make content of `resource/` world writeable in Docker

[DrYak]

Describe the bug

some container platform (e.g. Singularity) do not always run as "root" within the container.
this prevents writing into resource/ e.g. when indexing reference sequence

see:

• SIB GitLab issue 612
• FIX used at SIB SPSP

To Reproduce

• V-pipe used with a virus base config (with built-in reference in resources/)
• Singularity configured to pass-through username.
• rule ref_bwa_index crashes as the reference FASTA in resources/ belongs to root, not to the username that gets passed through.

Expected behavior

• V-pipe should index the reference in resource/