Update index.md (#1620)

Author: Arman-Hosseini

docs/index.md

@@ -2,9 +2,8 @@
 
 ![Logo](./assets/logo.svg)
 
-PhpSpreadsheet is a library written in pure PHP and providing a set of
-classes that allow you to read from and to write to different
-spreadsheet file formats, like Excel and LibreOffice Calc.
+PhpSpreadsheet is a library written in pure PHP and offers a set of classes that
+allow you to read and write various spreadsheet file formats such as Excel and LibreOffice Calc.
 
 ## File formats supported