chore(docs): add documentation for exp CLI commands (#20019)

Updates task documentation with experimental CLI.
~Generated by Claude using `--help` output.~

Should be merged alongside https://github.com/coder/coder/pull/20020

cli/exp_task_status.go

@@ -44,7 +44,17 @@ func (r *RootCmd) taskStatus() *serpent.Command {
 		watchIntervalArg time.Duration
 	)
 	cmd := &serpent.Command{
-		Short:   "Show the status of a task.",
+		Short: "Show the status of a task.",
+		Long: FormatExamples(
+			Example{
+				Description: "Show the status of a given task.",
+				Command:     "coder exp task status task1",
+			},
+			Example{
+				Description: "Watch the status of a given task until it completes (idle or stopped).",
+				Command:     "coder exp task status task1 --watch",
+			},
+		),
 		Use:     "status",
 		Aliases: []string{"stat"},
 		Options: serpent.OptionSet{