func MustRegisterTemplate(slo SLO, rules ...rulefmt.Rule) {
	Templates[reflect.TypeOf(slo).Name()] = slo
	TemplateRules = append(TemplateRules, rules...)
}
MustRegisterTemplate installs the rules that map template specific SLO intermediate
calculations to the job:slo_error:ratio<I> series that power alerts. This is called
from the place a template is implemented.
package templates
import (
	"reflect"
	"time"
	"github.com/prometheus/common/model"
	"github.com/prometheus/prometheus/pkg/rulefmt"
)