Review documentation for Weld 5

We should go over the documentation and make at least a quick overall review until we reach CR/Final release of Weld 5.

Known needed changes:

• Review any versions mentioned (weld, cdi, wfly, servlets, ...)
• Servlet parts is probably very much off and at least now (early Dec) we aren't able to test servlets at all
• Document changes between versions 4 and 5
  • Mention how build compatible extensions are executed (and that its integrator responsibility)
  • Changes in bean discovery and the need for legacy option on empty beans.xml discovery