Sample Open Horizon Agent pattern should be multi-arch

[johnwalicki]

The example Open Horizon Agent pattern listed in the setup instructions
is amd64. It would be better if the user could also register the pattern on an ARM based edge device.

Request to make the example pattern a multi-arch container.

The IBM team has used the Docker buildx experimental feature to build multi-arch containers.

[johnwalicki]

I would be happy to take on this task. I've built multi-arch containers for other projects.
I can't quite figure out where this example pattern / container is sourced from however.

[johnwalicki]

Proposed changes would be to
https://github.com/edgexfoundry-holding/open-horizon-integration/blob/master/hub/04-configure-anax.md
and the config files in
https://github.com/edgexfoundry-holding/open-horizon-integration/tree/master/hub/configs

[joewxboy]

@haveroot is refactoring the documentation, most likely in a new branch. @johnwalicki can you ping him and determine which version of the configure-anax doc you'll be changing? I'd like to ensure that your work doesn't get lost in the refactoring.

[joewxboy]

@johnwalicki please go ahead and submit a PR on this issue, and I'll have @mosquito provide you with past samples to ensure continuity/alignment.