Add example (set property to relationship) to SET page (#598) (#599)

Author: JPryce-Aklundh

modules/ROOT/pages/clauses/set.adoc

@@ -38,7 +38,7 @@ CREATE
 [[set-set-a-property]]
 == Set a property
 
-Use `SET` to set a property on a node or relationship:
+Update a node property:
 
 .Query
 [source, cypher, indent=0]
@@ -59,6 +59,26 @@ The newly-changed node is returned by the query.
 Properties set: 1
 |===
 
+Update a relationship property: 
+
+.Query
+[source, cypher, indent=0]
+----
+MATCH (n:Swedish {name: 'Andy'})-[r:KNOWS]->(m)
+SET r.since = 1999
+RETURN r, m.name AS friend
+----
+
+.Result
+[role="queryresult",options="header,footer",cols="2*<m"]
+|===
+| r | friend 
+| [:KNOWS {since: 1999}] | "Peter"
+2+d|Rows: 1 +
+Properties set: 1
+|===
+
+
 It is possible to set a property on a node or relationship using more complex expressions.
 For instance, in contrast to specifying the node directly, the following query shows how to set a property for a node selected by an expression: