man/man1/0intro.1: update supported systems.
LGTM=rsc
R=rsc
https://codereview.appspot.com/71070050
diff --git a/man/man1/0intro.1 b/man/man1/0intro.1
index 5245725..1c1ac3b 100644
--- a/man/man1/0intro.1
+++ b/man/man1/0intro.1
@@ -14,12 +14,14 @@
applications, and services from Plan 9
on Unix-like systems.
It runs on
-FreeBSD (x86),
-Linux (x86 and PowerPC),
-Mac OS X (PowerPC),
-OpenBSD (x86),
+FreeBSD (x86, x86-64),
+Linux (x86, x86-64, PowerPC and ARM),
+Mac OS X (x86, x86-64, and PowerPC),
+NetBSD (x86 and PowerPC),
+OpenBSD (x86 and PowerPC),
+Dragonfly BSD (x86-64),
and
-SunOS (Sparc).
+SunOS (x86-64 and Sparc).
.SS Commands
Plan 9 from User Space expects its own directory tree,
conventionally
