Update introduction.md

Added missing "is" in the first sentence.
Closes: #1067
Approved by: cgwalters

diff --git a/docs/manual/introduction.md b/docs/manual/introduction.md
index 6cde8dddf6e4a58fc832d95c50b098037f773a69..ec44999867a6e1ea38c34550f2938368e974ccfe 100644 (file)
--- a/docs/manual/introduction.md
+++ b/docs/manual/introduction.md
@@ -2,7 +2,7 @@
 
 ## Introduction
 
-OSTree an upgrade system for Linux-based operating systems that
+OSTree is an upgrade system for Linux-based operating systems that
 performs atomic upgrades of complete filesystem trees.  It is
 not a package system; rather, it is intended to complement them.
 A primary model is composing packages on a server, and then