New comment by flexibeast on void-packages repository

https://github.com/void-linux/void-packages/pull/21263#issuecomment-618366087

Comment:
Unfortunately, since this is a pre-release version, rather than [an official release](https://ftp.gnu.org/gnu/emacs/), this cannot be included in the Void repos, as per [CONTRIBUTING](https://github.com/void-linux/void-packages/blob/master/CONTRIBUTING.md).

(The first official release in the 27 series will be 27.1.)