Improved archives plugin

Hi @rhukster,

I don't know where to put it in, but I heavily improved the archives plugin and I would like to have some reviews before I issue a pull request, see the develop branch at

https://github.com/Sommerregen/grav-plugin-archives .

What do you think?

Wow you did a lot of work there! My thoughts are that because your modifications take the plugin quite a bit beyond the original concept, it's probably worth having it as a whole new plugin?

I think it should be called "HiearchialArchives" or "ArchivesPlus" or something like that? It's not an issue to do this.

Oh, my intention was not to derive another plugin, since my improvements are based on your code and it completeley behaves as your Archives plugin by setting

show:
   year: false;
   month: true;

limit:
   year: 0
   month: 0
   items: 0

in archives.yaml. However I plan to it a little bit more i.e. I think of an archives page. In this case it is maybe a good idea to rename mine. ArchivePlus is a good name! :-)

BTW: When modifying content in the onPageContentProcessed method, it is possible to attach a template, such that this content is rendered with the new template? The SimpleSearch plugin is maybe a good start. However I like to modify the content only without changing the layout of the whole site... How can I do that?