docs/guides/debugging.md: recommend symlinking instead of installing
docs/guides/debugging.md: recommend symlinking instead of installing

When setting up the env. Install no longer works as it depends on
systemd.

Signed-off-by: Botond Dénes <a584fa4d75a0a85d721f44fb6e06315a2853b0b6@scylladb.com>
Message-Id: <20210819110419.159351-1-a584fa4d75a0a85d721f44fb6e06315a2853b0b6@scylladb.com>

scylladb/scylla,scylladb/scylla,scylladb/scylla,scylladb/scylla