This commit adds documentation for zero-token nodes and an explanation
of how to use them to set up an arbiter DC to prevent a quorum loss
in multi-DC deployments.
The commit adds two documents:
- The one in Architecture describes zero-token nodes.
- The other in Cluster Management explains how to use them.
We need separate documents because zero-token nodes may be used
for other purposes in the future.
In addition, the documents are cross-linked, and the link is added
to the Create a ScyllaDB Cluster - Multi Data Centers (DC) document.
Refs https://github.com/scylladb/scylladb/pull/19684
Fixes https://github.com/scylladb/scylladb/issues/20294
Closes scylladb/scylladb#21348
(cherry picked from commit 9ac0aa7bba)
Closes scylladb/scylladb#23200