perf archive: Add documentation

This also makes it appear on the 'perf --help' output, i.e.
util/generate-cmdlist.sh now takes it into account.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <1263837559-24168-1-git-send-email-acme@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

tools/perf/Documentation/perf-archive.txt

+perf-archive(1)
+===============
+
+NAME
+----
+perf-archive - Create archive with object files with build-ids found in perf.data file
+
+SYNOPSIS
+--------
+[verse]
+'perf archive' [file]
+
+DESCRIPTION
+-----------
+This command runs runs perf-buildid-list --with-hits, and collects the files
+with the buildids found so that analisys of perf.data contents can be possible
+on another machine.
+
+
+SEE ALSO
+--------
+linkperf:perf-record[1], linkperf:perf-buildid-list[1], linkperf:perf-report[1]

tools/perf/command-list.txt

@@ -3,7 +3,7 @@
 # command name			category [deprecated] [common]
 #
 perf-annotate			mainporcelain common
-perf-archive			mainporcelain
+perf-archive			mainporcelain common
 perf-bench			mainporcelain common
 perf-buildid-list		mainporcelain common
 perf-diff			mainporcelain common