Small readme and missing sample file

Author: aprokopenko

README.md

@@ -1 +1,29 @@
-# sample-file
+# Sample File
+
+Simple classes to get real file sample for test purposes. May be used in phpunit tests for example.
+
+Files were taken from public resources over internet.
+
+## Usage
+
+```php
+use JustCoded\SampleFile\Image;
+use JustCoded\SampleFile\Document;
+use JustCoded\SampleFile\Sheet;
+
+
+$imagePath = Image::make()
+    ->png() // or jpg()
+    ->medium()
+    ->path();
+    
+$docPath = Document::make()
+    ->docx()
+    ->path();
+
+$sheetPath = Sheet::make()
+    ->xlsx()
+    ->path();
+```
+
+Your IDE will help you with available methods and options :).