doc/glossary: add "PLP" to glossary

Add "PLP" to the glossary.

Co-authored-by: Anthony D'Atri <[email protected]>
Signed-off-by: Zac Dover <[email protected]>

Author: zdover23

doc/glossary.rst

@@ -402,7 +402,15 @@
                 placement group, and each placement group belongs to exactly
                 one Ceph pool. 
 
+        PLP 
+                **P**\ower **L**\oss **P**\rotection. A technology that
+                protects the data of solid-state drives by using capacitors to
+                extend the amount of time available for transferring data from
+                the DRAM cache to the SSD's permanent memory. Consumer-grade
+                SSDs are rarely equipped with PLP.
+
 	:ref:`Pool<rados_pools>`
+
 		A pool is a logical partition used to store objects.
 
 	Pools