Create a sitemap for docs.wildfly.org

I've seen that google reports pages from various versions of our docs as the 'canonical' version of the page.[1] This is understandable, as google has no way know what's 'canonical', e.g. that the 17 folder is more relevant than the 14 folder and in many cases the pages themselves are identical. But I presume this will mean docs searches are more likely to direct people to older docs versions.

Of the various ways to improve this, the one that seems possibly practical is to add a sitemap file[2]. There are way too many pages to cover them all, but perhaps covering the root page for the version plus the root page of the various documents (Admin Guide, Developer Guide, etc) will suffice to get crawlers to focus on those pages, and then the rest will be ranked appropriately based on crawling from those roots. Or not; I'm no SEO SME.

Part of the PR for adding docs for a new release would then be to update the sitemap doc, e.g. to replace '17' in URLs with '18'.

jperkins-rhn FYI.

[1] https://support.google.com/webmasters/answer/139066
[2] https://support.google.com/webmasters/answer/183668?hl=en&ref_topic=4581190