Github-suggested Rust workflow

[eamsden]

This gets us basic "it builds and tests or no merge for you" CI courtesy GitHub suggesting a CI setup and @philipcmonk noticing the suggestion.

cc @lukestiles

[ashelkovnykov]

LGTM. Tested on my own fork and it ran successfully in the PR as well. No tests yet, but the workflow is ready.

We will want to setup a branch protection rule for status that the "Ares" workflow is required to pass for GitHub to allow merging.

@eamsden on the topic of merging, I don't have permissions for this repo to merge.

[eamsden]

@ashelkovnykov you can now.

@zalberico can you add @ashelkovnykov to the urbit org and to the New Mars team?

[zalberico]

He was already in the urbit org, but is now added to the new mars team

[ashelkovnykov]

Still unauthorized to approve merges:

I think the issue is that I only have "write" permissions for the repo in the New Mars team. I believe I need "maintainer" permissions.

@zalberico @eamsden @philipcmonk

[zalberico]

@ashelkovnykov made you a maintainer