Add support for providing args in a file (#1441) (#1442)

Cherry-picked from #1441

Author: renetapopova

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

@@ -9,8 +9,11 @@
 Both are installed as part of the product and can be executed with a number of commands.
 The `neo4j` commands are equivalent to the most important commands in the `neo4j-admin` server category.
 
-`help` and `version` are special commands and can be invoked with both `neo4j-admin` and `neo4j`.
-They are described in more detail in the <<_version_command>> and <<_help_command>> sections.
+Both `neo4j-admin` and `neo4j` commands support the <<help_command, `--help`>> option, which prints the command's usage and options, and the <<version_command, `--version`>> option, which prints the version of the command.
+All admin command options can also be provided in a file and passed to the command using the `@` prefix.
+This is useful when the command line becomes too long to manage.
+For example, `neo4j-admin database import full @/path/to/your/<args-filename> mydb`.
+For more information, see link:https://picocli.info/#AtFiles[Picocli -> AtFiles] official documentation.
 
 [NOTE]
 ====

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

@@ -343,6 +343,20 @@ neo4j-admin database import full --format=high_limit
 The `high_limit` format is available for Enterprise Edition only.
 ====
 
+[NOTE]
+.Providing arguments in a file
+====
+All options can be provided in a file and passed to the command using the `@` prefix.
+This is useful when the command line becomes too long to manage.
+For example, the following command:
+
+[source, shell]
+----
+neo4j-admin database import full @/path/to/your/<args-filename> mydb
+----
+For more information, see link:https://picocli.info/#AtFiles[Picocli -> AtFiles] official documentation.
+====
+
 [[import-tool-examples]]
 === Examples