doc: linkify .setupMaster() in cluster doc

Refs: #30163
PR-URL: #30204
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: David Carlier <devnexen@gmail.com>
Reviewed-By: Gireesh Punathil <gpunathi@in.ibm.com>

doc/api/cluster.md

@@ -644,11 +644,11 @@ added: v0.7.1
 
 * `settings` {Object}
 
-Emitted every time `.setupMaster()` is called.
+Emitted every time [`.setupMaster()`][] is called.
 
 The `settings` object is the `cluster.settings` object at the time
-`.setupMaster()` was called and is advisory only, since multiple calls to
-`.setupMaster()` can be made in a single tick.
+[`.setupMaster()`][] was called and is advisory only, since multiple calls to
+[`.setupMaster()`][] can be made in a single tick.
 
 If accuracy is important, use `cluster.settings`.
 
@@ -710,7 +710,7 @@ added: v0.11.2
 The scheduling policy, either `cluster.SCHED_RR` for round-robin or
 `cluster.SCHED_NONE` to leave it to the operating system. This is a
 global setting and effectively frozen once either the first worker is spawned,
-or `cluster.setupMaster()` is called, whichever comes first.
+or [`.setupMaster()`][] is called, whichever comes first.
 
 `SCHED_RR` is the default on all operating systems except Windows.
 Windows will change to `SCHED_RR` once libuv is able to effectively