Add docs about calling reset

Ref jsonrainbow/issues/385

Author: Andrew Boyton

README.md

@@ -45,6 +45,8 @@ if ($validator->isValid()) {
 }
 ```
 
+If you are validating multiple things then you should call `$$validator->reset();` between calls to `$validator->validate()`. See https://github.com/justinrainbow/json-schema/issues/385
+
 ### Type coercion
 
 If you're validating data passed to your application via HTTP, you can cast strings and booleans to
@@ -83,6 +85,7 @@ is_int($request->refundAmount); // true
 ```
 
 A shorthand method is also available:
+
 ```PHP
 $validator->coerce($request, $schema);
 // equivalent to $validator->validate($data, $schema, Constraint::CHECK_MODE_COERCE_TYPES);
@@ -177,21 +180,22 @@ $jsonValidator->validate($jsonToValidateObject, $jsonSchemaObject);
 ```
 
 ### Configuration Options
+
 A number of flags are available to alter the behavior of the validator. These can be passed as the
 third argument to `Validator::validate()`, or can be provided as the third argument to
 `Factory::__construct()` if you wish to persist them across multiple `validate()` calls.
 
-| Flag | Description |
-|------|-------------|
-| `Constraint::CHECK_MODE_NORMAL` | Validate in 'normal' mode - this is the default |
-| `Constraint::CHECK_MODE_TYPE_CAST` | Enable fuzzy type checking for associative arrays and objects |
-| `Constraint::CHECK_MODE_COERCE_TYPES` | Convert data types to match the schema where possible |
-| `Constraint::CHECK_MODE_EARLY_COERCE` | Apply type coercion as soon as possible |
-| `Constraint::CHECK_MODE_APPLY_DEFAULTS` | Apply default values from the schema if not set |
-| `Constraint::CHECK_MODE_ONLY_REQUIRED_DEFAULTS` | When applying defaults, only set values that are required |
-| `Constraint::CHECK_MODE_EXCEPTIONS` | Throw an exception immediately if validation fails |
-| `Constraint::CHECK_MODE_DISABLE_FORMAT` | Do not validate "format" constraints |
-| `Constraint::CHECK_MODE_VALIDATE_SCHEMA` | Validate the schema as well as the provided document |
+| Flag                                            | Description                                                   |
+| ----------------------------------------------- | ------------------------------------------------------------- |
+| `Constraint::CHECK_MODE_NORMAL`                 | Validate in 'normal' mode - this is the default               |
+| `Constraint::CHECK_MODE_TYPE_CAST`              | Enable fuzzy type checking for associative arrays and objects |
+| `Constraint::CHECK_MODE_COERCE_TYPES`           | Convert data types to match the schema where possible         |
+| `Constraint::CHECK_MODE_EARLY_COERCE`           | Apply type coercion as soon as possible                       |
+| `Constraint::CHECK_MODE_APPLY_DEFAULTS`         | Apply default values from the schema if not set               |
+| `Constraint::CHECK_MODE_ONLY_REQUIRED_DEFAULTS` | When applying defaults, only set values that are required     |
+| `Constraint::CHECK_MODE_EXCEPTIONS`             | Throw an exception immediately if validation fails            |
+| `Constraint::CHECK_MODE_DISABLE_FORMAT`         | Do not validate "format" constraints                          |
+| `Constraint::CHECK_MODE_VALIDATE_SCHEMA`        | Validate the schema as well as the provided document          |
 
 Please note that using `CHECK_MODE_COERCE_TYPES` or `CHECK_MODE_APPLY_DEFAULTS` will modify your
 original data.