release version 1.0.0

[edwardhartnett]

After #499 is merged, we can do the 1.0.0 release.

Suggest you copy the basic format of release notes from here: https://github.com/NOAA-EMC/NCEPLIBS-g2/releases

Make sure the name of the release tag is "v1.0.0". When you enter that name, it should offer you a button to create the tag on publish, like this:

For all future releases, follow the exact pattern of tag name: vX.Y.Z, where X.Y.Z are the version numbers. Never vary from this pattern.

The release title should be:

rrfs-workflow-1.0.0

For this release, you can sum up some current major features if you like. For the next release, you will easily be able to see what has changed since the last release and list it.

[edwardhartnett]

Done!