Use priorities when bootstrapping replica in supervised mode

Product: Tarantool
Since: 3.3.0
Root document:

• https://www.tarantool.io/en/doc/latest/reference/configuration/configuration_reference/
• (?) https://www.tarantool.io/en/doc/latest/platform/replication/supervised_failover/
  SME: @ georgiy-belyanin

Details

Now, when working in replication.failover = supervised mode the
instance priorities specified in the
failover.replicasets.<replicaset-name>.priority section are used
to select the bootstrap leader when using bootstrap_strategy: auto.
The replica with the highest priority is chosen as a bootstrap leader.
If there are more than one instance with the highest priority the first
one sorted by name alphabetically is chosen.

Example:

replication:
  failover: supervised
failover:
  replicasets:
    replicaset-001:
      priority:
        instance-002: 5
        instance-003: -3
        instance-004: 5

Setting up the config like this will make Tarantool choose
instance-002 as the bootstrap leader.
Requested by @georgiy-belyanin in https://github.com/tarantool/tarantool/commit/2eee236f1e866a53daf1b02832ee022727770d22.

Start with the configuration reference and supervised failover documentation linked in the issue, then compare their current descriptions of bootstrap_strategy and replica priorities with the requested behavior. Document highest-priority leader selection and alphabetical name tie-breaking, and verify the YAML example is represented accurately in both relevant pages.