change laravel-translatable vendor name

Author: ahmed-aliraqi

README.md

@@ -21,7 +21,7 @@
 
  * Simple key-value storage
  * Localization supported.
- * Localization using [dimsav/laravel-translatable](https://github.com/dimsav/laravel-translatable) Structure
+ * Localization using [Astrotomic/laravel-translatable](https://github.com/Astrotomic/laravel-translatable) Structure
 
 ## Installation