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_logs.go

@@ -26,6 +26,11 @@ func (r *RootCmd) taskLogs() *serpent.Command {
 	cmd := &serpent.Command{
 		Use:   "logs <task>",
 		Short: "Show a task's logs",
+		Long: FormatExamples(
+			Example{
+				Description: "Show logs for a given task.",
+				Command:     "coder exp task logs task1",
+			}),
 		Middleware: serpent.Chain(
 			serpent.RequireNArgs(1),
 		),