fix typo

Author: KlausBlum

Release Notes.txt

@@ -18,7 +18,7 @@ Changes to OOoLilyPond 0.5.0 since 0.4.0/0.4.1:
 * user interface can be translated into other languages
 
 Compatibility: OOoLilyPond (OLy) works with recent versions of LibreOffice (5.3.0.3) and OpenOffice (4.1.3). Older versions should work as well. It has even been tested with OpenOffice 2.4 without issues. 
-Any content (LilyPond code, templatex, OLy configuration files) created with/for OLy 0.4.x will work with OLy 0.5.x - and vice versa. (Fully compatible, forward and backward.)
+Any content (LilyPond code, templates, OLy configuration files) created with/for OLy 0.4.x will work with OLy 0.5.x - and vice versa. (Fully compatible, forward and backward.)
 Older snippets created with OLy 0.3.x will also work with 0.4.x and 0.5.x, but not (necessarily) vice versa.