Map expressions (neo4j#1236)

Author: JPryce-Aklundh

modules/ROOT/content-nav.adoc

@@ -73,6 +73,7 @@
 ** xref:expressions/string-operators.adoc[]
 ** xref:expressions/temporal-operators.adoc[]
 ** xref:expressions/list-expressions.adoc[]
+** xref:expressions/map-expressions.adoc[]
 ** xref:expressions/conditional-expressions.adoc[]
 
 * xref:functions/index.adoc[]

modules/ROOT/pages/expressions/index.adoc

@@ -15,5 +15,6 @@ For details and examples of specific expressions, see the following sections:
 * xref:expressions/string-operators.adoc[]: `+`, `||`
 * xref:expressions/temporal-operators.adoc[]: `+`, `-`, `*`, `/`
 * xref:expressions/list-expressions.adoc[]: information about list concatenation operators (`||`, `+`), list element access, list slicing, and list as well as pattern comprehensions.
+* xref:expressions/map-expressions.adoc[]: information about map operators (`.`, `[]`) and map projection.
 * xref:expressions/conditional-expressions.adoc[]