[cantarell-fonts] README: Correct extra bold master name

[Nikolaus Waxweiler <nwaxweiler src gnome org>]

commit ab5ba45e658c2db087d6176f87da7057d15ca122
Author: Nikolaus Waxweiler <madigens gmail com>
Date:   Sat May 18 00:24:13 2019 +0100

    README: Correct extra bold master name

 README.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/README.md b/README.md
index 4f753d64..0507d2ea 100644
--- a/README.md
+++ b/README.md
@@ -21,7 +21,7 @@ ninja -C build install
 Contributing
 ------------
 
-Cantarell consists of three masters: Thin (Cantarell-Light.ufo), Regular (Cantarell-Regular.ufo) and Extra 
Bold (Cantarell-ExtraBold.ufo). The file that ties them together and defines where the masters and instances 
stand is Cantarell.designspace.
+Cantarell consists of three masters: Thin (Cantarell-Light.ufo), Regular (Cantarell-Regular.ufo) and Extra 
Bold (Cantarell-Bold.ufo). The file that ties them together and defines where the masters and instances stand 
is Cantarell.designspace.
 
 If you want to contribute, you should be familiar with font design applications. You will also unfortunately 
have to learn about the innards of the UFO format as you go, to know what is changing... FontForge, TruFont 
and RoboFont can open the UFO v3 masters directly, Glyphs is tied to UFO v2 at the time of this writing.