Depreciated this repo / Mark as depreciated

[XtremeOwnageDotCom]

Seriously-

Update the website to show that k3os is not being maintained or updated.

Set this repo as depreciated.

SInce SUSE acquired Rancher, this project has been dead.

Last commit over a year ago.

At least do the community a favor, depreciate this repo and update your website so that people aren't installing something that you do not support, maintain, or even handle PRs for.

[FLYBYME]

If your looking to update k3s to something new than 1.19 its easy to fork and build to project. To ranchers credit they did very good work with this project.