Documentation is updated to reflect new functionality

Author: FlyingDR

README.md

@@ -1,5 +1,7 @@
 # css-classes
-Simple library to manage list of CSS classes. It simplifies tasks of constructing list of CSS classes from given information, adding and removing classes from the list.
+Simple library to manage a list of CSS classes. 
+
+It simplifies tasks of constructing a list of CSS classes from given information, adding and removing classes from the list.
 
 ## Installation
 
@@ -11,19 +13,23 @@ composer require flying/css-classes
 
 ## Standalone usage
 
-Functionality is exposed via [`\Flying\Util\Css\Classes`](src/Classes.php) class. 
+Functionality is exposed via [`Classes`](src/Classes.php) and [`MutableClasses`](src/MutableClasses.php) classes, both implements same [`ClassesInterface`](src/ClassesInterface.php) interface.
+
+Further documentation uses immutable `Classes` implementation as an example unless explicitly defined otherwise, but `MutableClasses` have exactly same usage in except of mutability.
 
 ### Accepted values
 
-Any method that is mean to accept CSS classes actually accepts arbitrary amount of arguments of any type (`mixed ...$classes`). Given arguments are processed in this way:
+Any method that is mean to accept CSS classes actually accepts arbitrary number of arguments of any type (`mixed ...$classes`).
+
+Given arguments are processed in this way:
 
  - Iterables are expanded
  - Nested values are flattened
  - Any values besides non-empty strings are ignored
 
 ### Immutability
 
-Class is immutable by its nature, so all mutation methods of the class returns new instance.
+v1 provides only immutable implementation. Since v2 there are both immutable `Classes` and mutable `MutableClasses` implementations.
 
 ### List creation
 
@@ -48,28 +54,43 @@ echo $classes;
 echo count($classes);
 ```
 
+Fluent interface is also possible to use:
+
+```php
+$classes = Classes::from('foo', 'bar baz', ['a', 'b', 'c'])
+    ->without('baz')
+    ->filter(fn(string $class): bool => strlen($class) > 1)
+    ->with('x', null, true, false, 42, 1.2345, ['y', ['z']]);
+// Outputs: foo bar x y z
+echo $classes;
+// Outputs: 5
+echo count($classes);
+```
+
 ### Classes list modification
 
-These methods can be used to modify list of CSS classes:
+These methods can be used to modify the list of CSS classes:
 
  - `with(...$classes)` - Add given CSS classes to the list
  - `without(...$classes)` - Remove given CSS classes from the list
  - `filter(callable $filter)` - Filter CSS classes list using provided filter. `$filter` signature is `(string $class): bool`
- - `clear()` - Remove all CSS classes from the list. Taking [immutability](#immutability) in consideration it is equivalent of `new Classes()`.
+ - `clear()` - Remove all CSS classes from the list. For [immutable](#immutability) `Classes` implementation it is equivalent of `new Classes()`.
 
 ### Classes list exporting
 
-Classes list can be exported as a plain array using `toArray()` method. Also class implements `ArrayAggregate` and `Stringable` interfaces, so it is also possible to iterate classes list and cast its value into string.
+Classes list can be exported as a plain array using `toArray()` method.
+
+Also, `ClassesInterface` interface extends `ArrayAggregate` and `Stringable` interfaces, so it is also possible to iterate over the list of CSS classes and cast its value into string.
 
 ### Other methods
 
-`Classes` implements `Countable` interface, so amount of available CSS classes can be calculated using `count()` PHP function or by calling `count()` method. 
+`ClassesInterface` extends `Countable` interface, so number of available CSS classes can be calculated using `count()` PHP function or by calling `count()` method. 
 
-It is also possible to check if given class is available in list by using `has(string $class)` method.
+It is also possible to check if given CSS class is available in the list by using `has(string $class)` method.
 
 ### Standalone `classes()` function
 
-For simple cases when it is only need to create CSS classes list as a string from available data it is also possible to use `\Flying\Util\Css\classes()` function.
+For simple cases when it is only needs to create CSS classes list as a string from available data it is also possible to use `\Flying\Util\Css\classes()` function.
 
 `classes()` function is available since v1.1.0
 
@@ -102,7 +123,9 @@ But it is also possible to use CSS classes list modification methods:
 </ul>
 ```
 
-Refer to the [Twig documentation](https://twig.symfony.com/doc/3.x/api.html#using-extensions) on how to add extension to the Twig. 
+Refer to the [Twig documentation](https://twig.symfony.com/doc/3.x/api.html#using-extensions) on how to add the extension to the Twig. 
+
+For Symfony, there is a [separate bundle](https://github.com/FlyingDR/css-classes-bundle) to simplify integration.
 
 ## License