placement of docs/RELEASE.html

[andy5995]

I forgot about this file. Not sure it's needed anymore. It all applies to htdig, and we already link to them for reference purposes. I'm not sure if the web site links to it. If so, not from the home page.

https://github.com/solbu/hldig/blob/master/docs/RELEASE.html

[solbu]

Yea, I think we can remove that. Release notes belong in a plain text file, such as the ChangeLog.