Add allowUnusedParametersBeforeUsed to README

Author: sirbrillig

README.md

@@ -64,6 +64,7 @@ The available options are as follows:
 
 - `allowUnusedFunctionParameters` (bool, default `false`): if set to true, function arguments will never be marked as unused.
 - `allowUnusedCaughtExceptions` (bool, default `false`): if set to true, caught Exception variables will never be marked as unused.
+- `allowUnusedParametersBeforeUsed` (bool, default `false`): if set to true, unused function arguments will be ignored if they follow used function arguments.
 - `validUnusedVariableNames` (string, default `null`): a space-separated list of names of placeholder variables that you want to ignore from unused variable warnings. For example, to ignore the variables `$junk` and `$unused`, this could be set to `'junk unused'`.
 - `ignoreUnusedRegexp` (string, default `null`): a PHP regexp string (note that this requires explicit delimiters) for variables that you want to ignore from unused variable warnings. For example, to ignore the variables `$_junk` and `$_unused`, this could be set to `'/^_/'`.
 - `validUndefinedVariableNames` (string, default `null`): a space-separated list of names of placeholder variables that you want to ignore from undefined variable warnings. For example, to ignore the variables `$post` and `$undefined`, this could be set to `'post undefined'`.