Document default REPLICATION in ADDJOB

README says:
> Disque is a synchronously replicated job queue. By default when a new job is added, it is replicated to W nodes before the client gets an acknowledgement about the job being added. W-1 nodes can fail and the message will still be delivered.

What is W by default?
When I add a job without the REPLICATE parameter to a cluster with 3 nodes, job info gives me 'repl 3'. A cluster with 1 node gives me 'repl 1'.
By default REPLICATE=min(cluster-size, 3) or REPLICATE=cluster-size?
This is important because if you don't specify REPLICATE on a cluster with 3 nodes and 1 is down, you won't be able to add jobs.

[ADDJOB doc](https://github.com/antirez/disque#addjob-queue_name-job-ms-timeout-replicate-count-delay-sec-retry-sec-ttl-sec-maxlen-count-async) doesn't specify the REPLICATE default value and behavior:

> REPLICATE count is the number of nodes the job should be replicated to.

The anchor text in the README is also wrong. Should be addjob instead of 'addjob-queue...'.

Why is the syntax of command and info different?
'REPLICATE 3' in command.
'repl 3' in info. Lowercase and shorter word.