Default to only environment & configurable default environment

[wbobeirne]

If you only have one environment, and you run a command that has an environment target (e.g. coder sh or coder sync) and you omit the target, we should just run the command against your only environment. Likewise, when you have multiple, you should be able to configure a default environment.

gcloud and kubectl both have default namespace / projects, so it would be similar to that.

Suggestion originally comes from @creack.

[creack]

Note that coder config-ssh uses the first env, but doesn't let you use a different one.

[cmoog]

Note that coder config-ssh uses the first env, but doesn't let you use a different one.

I do not think this is correct. It only gives an example using the first env but the SSH config file should get the spec for all of your environments. This command was modeled after gcloud compute config-ssh

[creack]

Note that coder config-ssh uses the first env, but doesn't let you use a different one.

I do not think this is correct. It only gives an example using the first env but the SSH config file should get the spec for all of your environments. This command was modeled after gcloud compute config-ssh

Indeed, I was confused as the output is an example and differs slightly from the other commands. I confirm it indeed generates the config for all env! my bad.