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/cliui/cliui.go

@@ -26,6 +26,7 @@ var Styles = struct {
 	Checkmark,
 	Code,
 	Crossmark,
+	Error,
 	Field,
 	Keyword,
 	Paragraph,
@@ -41,6 +42,7 @@ var Styles = struct {
 	Checkmark:     defaultStyles.Checkmark,
 	Code:          defaultStyles.Code,
 	Crossmark:     defaultStyles.Error.Copy().SetString("✘"),
+	Error:         defaultStyles.Error,
 	Field:         defaultStyles.Code.Copy().Foreground(lipgloss.AdaptiveColor{Light: "#000000", Dark: "#FFFFFF"}),
 	Keyword:       defaultStyles.Keyword,
 	Paragraph:     defaultStyles.Paragraph,