Update 'README.md'

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README.md

@@ -1,5 +1,7 @@
 # addprefix
 
-Script to rename all files with a extension with a prefix
-addprefix <prefix> <extension>
+Script to rename all files with a extension with a prefix.
+
+addprefix <prefix> <extension>
+
 Ex: addprefix "Hello-" txt