Fix Cypher Shell docs

Author: loveleif

modules/ROOT/pages/tools/cypher-shell.adoc

@@ -74,7 +74,7 @@ The syntax for running Cypher Shell is:
 |auto
 
 |-P PARAM, --param PARAM
-|Add a parameter to this session. Example: `-P {a: 1}`, `-P '{a: 1, b: duration({seconds: 1})}'`, or using arrow syntax `-P 'a => 1'`. This argument can be specified multiple times.
+|Add a parameter to this session. Example: `-P '{a: 1}'`, `-P '{a: 1, b: duration({seconds: 1})}'`, or using arrow syntax `-P 'a => 1'`. This argument can be specified multiple times.
 |[]
 
 |--non-interactive