Update README.MD

Make clear in the first sentence which problem this extension solves.

README.MD

@@ -1,9 +1,9 @@
 # SingleFile
 
-SingleFile is a Web Extension (and a CLI tool) compatible with Chrome, Firefox
+SingleFile helps you to save a complete web page into a single HTML
+file. SingleFile is a Web Extension (and a CLI tool) compatible with Chrome, Firefox
 (Desktop and Mobile), Microsoft Edge, Safari, Vivaldi, Brave, Waterfox, Yandex
-browser, and Opera. It helps you to save a complete web page into a single HTML
-file.
+browser, and Opera.
 
 ## Table of Contents