Supporting real number for samples data

[Bojun-Seo]

FlameGraph shows the number of samples in specific backtrace. Since it is the "number" of samples, it is an integer. But it can be expanded to real number. So I suggest to support real number for samples data. For example, think about the data like followings,

foo;bar;baz 0.156
foo;foo;bar;baz 0.98
foo;foo;foo;bar;baz 0.343
foo;foo;foo;foo;bar;baz 0.888

Every number of samples in flamegraph output svg file is 0 with the data.

I can see five decimal places of data if I change the code like followings.

$ git diff
diff --git a/flamegraph.pl b/flamegraph.pl
index 8c917ec..5855196 100755
--- a/flamegraph.pl
+++ b/flamegraph.pl
@@ -1233,7 +1233,7 @@ while (my ($id, $node) = each %Node) {

        # Add commas per perlfaq5:
        # https://perldoc.perl.org/perlfaq5#How-can-I-output-my-numbers-with-commas-added?
-       my $samples = sprintf "%.0f", ($etime - $stime) * $factor;
+       my $samples = sprintf "%.5f", ($etime - $stime) * $factor;
        (my $samples_txt = $samples)
                =~ s/(^[-+]?\d+?(?=(?>(?:\d{3})+)(?!\d))|\G\d{3}(?=\d))/$1,/g;