render content with user custom data

I want to use user custom data for rendering content, but couldn't.

config.pl
```Perl
+{
    hoge => 'fuga',
}
```

Template Class
```Perl
package Dist::Maker::Template::Hoge;
sub distribution {
    return <<'DIST';
@@ hoge.txt
<: $hoge :>
DIST
}
```

and run below command
```
dim --config config.pl init Dist::Sample Hoge
```

I couldn't do above, because there is bug that Dist::Maker::Config->data doesn't return data which is merged with user data.  So fix it.