Improve RingbufferStore documentation (#897)

- Reword the configuration heading to match that of `List`, `Set`, `Multimap` etc
- Fix formatting of property reference

(cherry picked from commit 5e86cac)

docs/modules/data-structures/pages/ringbuffer.adoc

@@ -295,9 +295,9 @@ hazelcast:
 ----
 ====
 
-The following are the explanations for the Ringbuffer store configuration elements:
+The following are the configuration elements and their descriptions:
 
-* `class-name: Name of the Ringbuffer store factory class.
+* `class-name`: Name of the Ringbuffer store factory class.
 
 [[configuring-ringbuffer-in-memory-format]]
 == Configuring Ringbuffer In-Memory Format