Add the ramfs recipe

Adds a recipe to https://gitlab.redox-os.org/redox-os/ramfs, which is a ramfs with write support (unlike initfs: which seems to silently discard writes). Some drivers that are spawned before redoxfs gets to initialize the file: scheme, like pcid, xhcid or redoxfs itself, might want some proper logging, which this scheme allows.

This daemon is also supposed to be included in the initfs, so that it can be spawned before pcid is initialized.