docs: validator config, early failure mode

Author: erosb

README.md

@@ -9,6 +9,9 @@
 * [Draft 4 or Draft 6?](#draft-4-or-draft-6)
 * [Investigating failures](#investigating-failures)
   * [JSON report of the failures](#json-report-of-the-failures)
+* [Configuring the validation](#validator-config)
+  * [Eary failure mode](#validator-config-early-failure)
+  * [Default value support](#validator-config-default-support)
 * [Format validators](#format-validators)
   * [Example](#example)
 * [Resolution scopes](#resolution-scopes)
@@ -40,7 +43,7 @@ Add the JitPack repository and the dependency to your `pom.xml` as follows:
 <dependency>
     <groupId>com.github.everit-org.json-schema</groupId>
     <artifactId>org.everit.json.schema</artifactId>
-    <version>1.6.1</version>
+    <version>1.7.0</version>
 </dependency>
 ...
 <repositories>
@@ -208,6 +211,42 @@ following keys:
 Please take into account that the complete failure report is a *hierarchical tree structure*: sub-causes of a cause can
 be obtained using `#getCausingExceptions()` .  
 
+## Configuring the validation
+
+If you call the `Schema#validate(input)` method then the validation will happen with a convenient mode which should meet the
+needs of most users for common scenarios. Though there can be cases where the default behaviour doesn't fit your needs. Then you can
+set some configuration values explicitly by manually creating a `Validator` instance and toggling some features in its builder, so 
+instead of calling `Schema.validate(input)`, your code will look something like this:
+
+```
+import org.everit.json.schema.Validator;
+...
+Validator validator = Validator.builder()
+	/* configuration comes here */
+	.build();
+validator.performValidation(schema, input);
+``` 
+
+_Note: the `Validator` class is immutable and thread-safe, so you don't have to create a new one for each validation, it is enough
+to configure it only once._
+
+### Early failure mode
+
+By default the validation error reporting in collecting mode (see the "Investigating failures" chapter). That is convenient for having a
+detailed error report, but under some circumstances it is more appropriate to stop the validation when a failure is found without
+checking the rest of the JSON document. To toggle this fast-failing validation mode you have to call the failEarly() method of
+ValidatorBuilder:
+
+```
+import org.everit.json.schema.Validator;
+...
+Validator validator = Validator.builder()
+	.failEarly()
+	.build();
+validator.performValidation(schema, input);
+```
+
+
 
 ## Format validators