Fix METADATA syntax.

Bug: N/A
Test: manual
Change-Id: Ie201b502a35d2c650f0ccd245eee26a53e1b298a
diff --git a/METADATA b/METADATA
index 47c310d..ee59102 100644
--- a/METADATA
+++ b/METADATA
@@ -1,6 +1,6 @@
 name: "one-true-awk"
 description:
-    "This is the version of awk described in "The AWK Programming Language", by "
+    "This is the version of awk described in 'The AWK Programming Language', by "
     "Al Aho, Brian Kernighan, and Peter Weinberger (Addison-Wesley, 1988, ISBN "
     "0-201-07981-X)."