make comment in sitemap optional

[bnomei]

i get the idea that giving you credit in the sitemap seems reasonable.

<!-- Sitemap generated using https://github.com/omz13/kirby3-xmlsitemap -->

but still i would like you to remove it or make it optional because:

• i value my clients and their customers security most. none of the code i use gives away directly what cms is used. so attackers do not know which cms was used. the new pages/media paths in thumbs might be a hint. no string reference to kirby whatsoever.
• your plugin could in theory expose an vulnerability and i would like to hide that as much as possible.

[bnomei]

oh its in the xsl as well.

[omz13]

An option to hide is planned.

Also, option to not do the style sheet (because that could be used as an identification vector).

[bvdputte]

+1