[Automatic Releases] Automatic Descriptions for each weekly release

[AsherGlick]

Each weekly release should have some sort of description so that users have at least a passing idea of what what added in that release. A list of all the commits might be too much, but a list of all the pull requests might be fine.

If we cannot determine a way to reasonably include useful information then we can construct a template description and fill it with a standard message for each weekly release. Such as

The weekly release for {year}-{month}-{day}

or something equally unassuming.