Add documentation

README.md

@@ -1,5 +1,11 @@
+[![Build Status](https://travis-ci.org/danielsdeboer/optionally.svg?branch=master)](https://travis-ci.org/danielsdeboer/optionally)
+[![Latest Stable Version](https://poser.pugx.org/aviator/optionally/v/stable)](https://packagist.org/packages/aviator/optionally)
+[![License](https://poser.pugx.org/aviator/optionally/license)](https://packagist.org/packages/aviator/optionally)
+
 ## Overview
 
+Optionally is a keyed store of booleans. It can be used for anything but usually to store options.
+
 ### Installation
 
 Via Composer:
@@ -18,7 +24,109 @@ composer test
 
 ### Usage
 
+Create a new instance with an array. The array should have string keys and boolean values. It's important to note that any integer keys will be silently discarded without raising an exception or error: 
+
+```php
+$options = Optionally::make(['option1' => true, 'option2' => false, 0 => false]);
+
+// [0 => false] will be discarded.
+```
+
+Get the underlying array with `all()`:
+
+```php
+$options->all();
+
+// ['option1' => true, 'option2' => false]
+```
+
+Get the keys of the underlying array with `keys()`:
+
+```php
+$options->keys();
+
+// ['option1', 'option2']
+```
+
+Get the value of a key if it exists (or null if it doesn't) with `get()`:
+
+```php
+$options->get('option1');
+
+// true
+
+$options->get('someOptionThatDoesntExist');
+
+// null
+```
+
+Find whether or not a key exists with `has()`:
+
+```php
+$options->has('option2');
+
+// true
+
+$options->has('someOptionThatDoesntExist');
+
+// false
+```
+
+Trash the existing options and replace them with `replaceWith()`:
 
+```php
+$options->replaceWith(['option3' => true, 'option4' => false]);
+
+$options->all();
+
+// ['option3' => true, 'option4' => false]
+```
+
+Add a new array to the existing options array, overwriting existing keys with `add()`:
+
+```php
+$options->add(['option1' => false, 'option3' => true]);
+
+$options->all();
+
+// ['option1' => false, 'option2' => false, 'option3' => true]
+```
+
+Set a single key value pair with `set()`:
+
+```php
+$options->set('option3', false);
+
+$options->all();
+
+// ['option1' => true, 'option2' => false, 'option3' => false]
+```
+
+Trash a single key value pair with `remove()`:
+
+```php
+$options->remove('option1');
+
+$options->all();
+
+// ['option2' => true]
+```
+
+An instance of `Optionally` is iterable:
+
+```php
+foreach ($options as $key => $value) {
+    /* ... */
+}
+```
+
+It's also countable:
+
+```php
+count($foreach);
+
+// 2
+```
 
 ## Other