Add section about Parquet header in admin import. (#2134)

Docs addition for admin import.
The feature will be get merged into the dev branch today.

---------

Co-authored-by: Reneta Popova <[email protected]>

Author: meistermeier

modules/ROOT/pages/tools/neo4j-admin/neo4j-admin-import.adoc

@@ -978,6 +978,20 @@ For example, you can use `uuid:ID(Person){label:Person}`, where the relationship
 * For examples of creating property uniqueness constraints, see link:{neo4j-docs-base-uri}/cypher-manual/current/constraints/managing-constraints/#create-property-uniqueness-constraints[Cypher Manual -> Create property uniqueness constraints].
 ====
 
+=== Extended header support for Parquet
+
+In addition to the header format supported by the CSV import, the Parquet import supports name-mapping header files.
+Those files contain two rows of entries, where the first row represents the name (incl. optional type, id group, etc.), and the second row references the name of the original columns in the data files.
+
+.movie_header.csv
+[source, csv]
+----
+movieId:ID,title,year:int,:LABEL
+id,movie_title,year,label
+----
+
+If a header file is provided for a set of labels or a relationship type, the importer will ignore columns not mentioned in the headers.
+
 [[import-tool-header-format-nodes]]
 == Node files