Added file input form element docs

The file input is in the API but not in the documentation.

laravel/documentation/views/forms.md

@@ -6,6 +6,7 @@ ## Contents
 - [CSRF Protection](#csrf-protection)
 - [Labels](#labels)
 - [Text, Text Area, Password & Hidden Fields](#text)
+- [File Input](#file)
 - [Checkboxes and Radio Buttons](#checkboxes-and-radio-buttons)
 - [Drop-Down Lists](#drop-down-lists)
 - [Buttons](#buttons)
@@ -114,6 +115,13 @@ #### Generating a checkbox that is checked by default:
 
 > **Note:** The *radio* method has the same signature as the *checkbox* method. Two for one!
 
+<a name="file"></a>
+## File Input
+
+#### Generate a file input element:
+
+	echo Form::file('image');
+
 <a name="drop-down-lists"></a>
 ## Drop-Down Lists