ICU-20892 Highlight `.cpyskip.txt` on GitHub.com
diff --git a/.gitattributes b/.gitattributes
index 251cad3..83661e6 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -81,3 +81,6 @@
 *.gz filter=lfs diff=lfs merge=lfs -text
 *.bz2 filter=lfs diff=lfs merge=lfs -text
 *.gif filter=lfs diff=lfs merge=lfs -text
+
+# Enable syntax highlighting on GitHub.com
+.cpyskip.txt linguist-language=Ignore-List