docs/scheduler/sched-bwc: formatting fix

Since commit d6a3b247 these three lines are merged into one by the
RST processor, making it hard to read. Use bullet points to separate
the entries, like it's done in other similar places.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20210120001824.385168-2-kolyshkin@gmail.comSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Documentation/scheduler/sched-bwc.rst

@@ -25,9 +25,10 @@ Management
 ----------
 Quota and period are managed within the cpu subsystem via cgroupfs.
 
-cpu.cfs_quota_us: the total available run-time within a period (in microseconds)
-cpu.cfs_period_us: the length of a period (in microseconds)
-cpu.stat: exports throttling statistics [explained further below]
+- cpu.cfs_quota_us: the total available run-time within a period (in
+  microseconds)
+- cpu.cfs_period_us: the length of a period (in microseconds)
+- cpu.stat: exports throttling statistics [explained further below]
 
 The default values are::