[wix-devs] VS2019 Preview 1 Early Preview support available

[Rob Mensching]

As discussed at the last WiX Online Meeting (https://www.firegiant.com/blog/2019/1/17/wix-online-meeting-162-highlights/), I've updated wixtoolset.org releases page (http://wixtoolset.org/releases/) to include a link to the direct download of the "Preview of WiX Toolset Visual Studio 2019 Preview 1 Extension" (I considered adding another "Preview" to the end but it looked a bit much).

Thanks again to Christopher Painter for doing the heavy lifting.