feat: Improve resource preview and first-time experience (#946)

* Improve CLI documentation

* feat: Allow workspace resources to attach multiple agents

This enables a "kubernetes_pod" to attach multiple agents that
could be for multiple services. Each agent is required to have
a unique name, so SSH syntax is:

`coder ssh <workspace>.<agent>`

A resource can have zero agents too, they aren't required.

* Add tree view

* Improve table UI

* feat: Allow workspace resources to attach multiple agents

This enables a "kubernetes_pod" to attach multiple agents that
could be for multiple services. Each agent is required to have
a unique name, so SSH syntax is:

`coder ssh <workspace>.<agent>`

A resource can have zero agents too, they aren't required.

* Rename `tunnel` to `skip-tunnel`

This command was `true` by default, which causes
a confusing user experience.

* Add disclaimer about editing templates

* Add help to template create

* Improve workspace create flow

* Add end-to-end test for config-ssh

* Improve testing of config-ssh

* Fix workspace list

* Fix config ssh tests

* Update cli/configssh.go

Co-authored-by: Cian Johnston <public@cianjohnston.ie>

* Fix requested changes

* Remove socat requirement

* Fix resources not reading in TTY

Co-authored-by: Cian Johnston <public@cianjohnston.ie>

cli/root.go

@@ -29,9 +29,10 @@ const (
 
 func Root() *cobra.Command {
 	cmd := &cobra.Command{
-		Use:          "coder",
-		Version:      buildinfo.Version(),
-		SilenceUsage: true,
+		Use:           "coder",
+		Version:       buildinfo.Version(),
+		SilenceErrors: true,
+		SilenceUsage:  true,
 		Long: `    ▄█▀    ▀█▄
      ▄▄ ▀▀▀  █▌   ██▀▀█▄          ▐█
  ▄▄██▀▀█▄▄▄  ██  ██      █▀▀█ ▐█▀▀██ ▄█▀▀█ █▀▀