perf timechart: Add example in the documentation

While at it, update the synopsis to show both forms.
Signed-off-by: NRamkumar Ramachandra <artagnon@gmail.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Namhyung Kim <namhyung@gmail.com>
Link: http://lkml.kernel.org/r/1380791716-10325-1-git-send-email-artagnon@gmail.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/Documentation/perf-timechart.txt

@@ -8,7 +8,8 @@ perf-timechart - Tool to visualize total system behavior during a workload
 SYNOPSIS
 --------
 [verse]
-'perf timechart' {record}
+'perf timechart' record <command>
+'perf timechart' [<options>]
 
 DESCRIPTION
 -----------
@@ -41,6 +42,18 @@ OPTIONS
 --symfs=<directory>::
         Look for files with symbols relative to this directory.
 
+EXAMPLES
+--------
+
+$ perf timechart record git pull
+
+  [ perf record: Woken up 13 times to write data ]
+  [ perf record: Captured and wrote 4.253 MB perf.data (~185801 samples) ]
+
+$ perf timechart
+
+  Written 10.2 seconds of trace to output.svg.
+
 SEE ALSO
 --------
 linkperf:perf-record[1]