Add doc for required rest positional arguments
diff --git a/flags.go b/flags.go
index 6656848..757d42a 100644
--- a/flags.go
+++ b/flags.go
@@ -138,7 +138,13 @@
then all remaining arguments will be added to it.
Positional arguments are optional by default,
unless the "required" tag is specified together
- with the "positional-args" tag (optional)
+ with the "positional-args" tag. The "required" tag
+ can also be set on the individual rest argument
+ fields, to require only the first N positional
+ arguments. If the "required" tag is set on the
+ rest arguments slice, then its value determines
+ the minimum amount of rest arguments that needs to
+ be provided (e.g. `required:"2"`) (optional)
positional-arg-name: used on a field in a positional argument struct; name
of the positional argument placeholder to be shown in
the help (optional)
