Added documentation for new parser configuration option

docs/index.adoc

@@ -1039,6 +1039,9 @@ assert(mixed.positional == Arrays.asList("param0", "param1", "param2", "param3")
 assert(mixed.options == Arrays.asList("AAA", "BBB"))
 ----
 
+Note that the mixing of positional parameters and options is configurable, see <<End of Options Behaviour>>.
+
+
 === Double dash (`--`)
 When one of the command line arguments is just two dashes without any characters attached (`--`),
 picocli interprets all following arguments as positional parameters, even arguments that match an option name.
@@ -5261,6 +5264,12 @@ java App -x -y -y=123
 ----
 
 
+=== End of Options Behaviour
+Since picocli 2.0, positional parameters can be specified anywhere on the command line and no longer need to follow the options.
+Starting with v4.8.0, `CommandLine::setParameterAllowedBeforeEndOfOptions` can be set to false in order to restrict
+the mixing of options and positional parameters.  This option forces positional parameters to follow the <<Double dash (`--`),End of Options delimiter>>.
+
+
 === Toggle Boolean Flags
 When a flag option is specified on the command line picocli will set its value to the opposite of its _default_ value.