Add a note to the install docs about websockets on arm64

[Jane Sandberg]

When installing on arm64, the install instructions work great, except for the wget URL for downloading websocketd.

It would be nice to add a small note to the install instructions to note that ARM64 binaries for websocketd are also available.

Patch forthcoming.

[Jane Sandberg (sandbergja)]

Branch here: user/sandbergja/lp1990020_arm64_readme

[Ben Shum (bshum)]

Testing this out with M1 macbook and Ubuntu arm64 VM and first glance, the zip file is pulling linux_arm version, not arm64. For my testing on an arm64 Ubuntu image, it appears that we need the arm64 websocketd package in order to start websocketd. The one that comes with the arm.zip is not compatible to start.

Continuing testing.

[Jane Sandberg (sandbergja)]

Thanks for catching that, Ben! I amended my commit, should be ready for re-review.