runtime(doc): fix typo "a xterm" -> "an xterm"
related: #15278
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/runtime/doc/mbyte.txt b/runtime/doc/mbyte.txt
index fcbded0..f02092b 100644
--- a/runtime/doc/mbyte.txt
+++ b/runtime/doc/mbyte.txt
@@ -493,7 +493,7 @@
terminal, if the terminal supports the same encoding that Vim uses. Thus this
is less flexible.
-For example, you can run Vim in a xterm with added multibyte support and/or
+For example, you can run Vim in an xterm with added multibyte support and/or
|XIM|. Examples are kterm (Kanji term) and hanterm (for Korean), Eterm
(Enlightened terminal) and rxvt.