time.1: minor cleanup (alignment/macro/spdx)

+ shorter example filename to minimize line wrap
+ standards macro clarifying posix => posix.2
+ align options + tag spdx

Reviewed by:	mhorne
MFC after:	3 days
Pull-Request:	https://github.com/freebsd/freebsd-src/pull/1315

usr.bin/time/time.1

@@ -1,3 +1,6 @@
+.\"-
+.\" SPDX-License-Identifier: BSD-3-Clause
+.\"
 .\" Copyright (c) 1980, 1991, 1993
 .\"	The Regents of the University of California.  All rights reserved.
 .\"
@@ -56,7 +59,7 @@ the time used to execute the
 process and the time consumed by system overhead.
 .Pp
 The following options are available:
-.Bl -tag -width indent
+.Bl -tag -width "-o file"
 .It Fl a
 If the
 .Fl o
@@ -143,8 +146,8 @@ file.
 Then execute the command again to make a new copy and add the result to the same
 file:
 .Bd -literal -offset indent
-$ /usr/bin/time -o times.txt cp FreeBSD-12.1-RELEASE-amd64-bootonly.iso copy1.iso
-$ /usr/bin/time -a -o times.txt cp FreeBSD-12.1-RELEASE-amd64-bootonly.iso copy2.iso
+$ /usr/bin/time -o times.txt cp source.iso copy1.iso
+$ /usr/bin/time -a -o times.txt cp source.iso copy2.iso
 .Ed
 .Pp
 The
@@ -190,7 +193,8 @@ sys 0.00
 .Sh STANDARDS
 The
 .Nm
-utility is expected to conform to ISO/IEC 9945-2:1993 (``POSIX'').
+utility is expected to conform to
+.St -iso9945-2-93
 .Sh HISTORY
 A
 .Nm