Update README.md

Author: o-rumiantsev

README.md

@@ -17,15 +17,14 @@ const parser = new Parser({
 });
 ```
 
-#### Parsing
-Just pass object or buffer to `parse` method, and specify schema name and version:
+#### Simple parsing
+Just pass object or buffer to `parse` method, and specify schema name:
 ```javascript
 const buffer = parser.parse(
   {
      ...
   },
-  'schemaName',
-  'latest' // default
+  'schemaName'
 );
 
 const obj = parser.parse(buffer, 'schemaName');
@@ -62,11 +61,23 @@ NOTE: if field's size is greater than 4 bytes(more than Int32), it should be pas
 
 
 #### Versions
-You can easily update schemas without losing older ones. For version updating use semver contract:
+For schemas updating and versioning you can use `versions` extension for parser. It works like:
+```javascript
+const parser = new Parser(/* schemas */) // create a simple parser
+const versioned = parser.versions() // here will be created a new parser instance, supporting versioning
+                                    // and old simple parser will not change after this
+```
+
+Using `versions` extension you can easily update schemas without losing older ones. For version updating use semver contract:
 ```javascript
 parser.updateSchema(
   schemaName,
   newSchema,
   updateType // 'major', 'minor' or 'patch'
 )
 ```
+
+You can also use any version of schema to parse data, just specify version as a last parameter of `parse` method, it is `latest` by default:
+```javascript
+parser.parse({ ... }, `schemaName`, `version`);
+```