minor: edits

Author: Sam Kleinman

source/reference/replica-configuration.txt

@@ -251,11 +251,12 @@ replica set configuration document. square brackets (e.g. ``[`` and
 
 .. _replica-set-reconfiguration-usage:
 
-use
+Use
 ---
 
-most modifications of replica set configuration use the
-:program:`mongo` shell. consider the following:
+Most modifications of :term:`replica set` configuration use the
+:program:`mongo` shell. Consider the following reconfiguration
+operation:
 
 .. example::