doc: ucrt-vs-msvcrt.txt: Fix typo

Signed-off-by: LIU Hao <lh_mouse@126.com>

mingw-w64-doc/howto-build/ucrt-vs-msvcrt.txt

diff --git a/mingw-w64-doc/howto-build/ucrt-vs-msvcrt.txt b/mingw-w64-doc/howto-build/ucrt-vs-msvcrt.txt
index 4d98a2f..3247ff6 100644
--- a/mingw-w64-doc/howto-build/ucrt-vs-msvcrt.txt
+++ b/mingw-w64-doc/howto-build/ucrt-vs-msvcrt.txt
@@ -48,7 +48,7 @@
 
 Windows 10 and newer systems have UCRT automatically preinstalled.
 
-Windows Vista / Server 2008, Windows 7 / Server 2008 R2, Widows 8 / Server 2012
+Windows Vista / Server 2008, Windows 7 / Server 2008 R2, Windows 8 / Server 2012
 and Windows 8.1 / Server 2012 R2 systems include UCRT libraries in KB2999226
 system update, which is available at website:
 https://support.microsoft.com/help/2999226