Move the RSS Macro from platform to contrib

Hi devs,

I’m not planning to do this now but I wanted us to decide if that’s something we want to do.

IMO the rss macro is not a core macro (there are actually not a lot of needs for it) and should be moved out of platform. This goes in the direction of our quest to reduce the size of XS.

I’m referring to xwiki-platform/xwiki-platform-core/xwiki-platform-rendering/xwiki-platform-rendering-macros/xwiki-platform-rendering-macro-rss at 227e20bdbe7ee2000ac4295814821f62e7527247 · xwiki/xwiki-platform · GitHub

WDYT?

Thanks