feat(event): adding more helpers.

event.go

@@ -141,3 +141,25 @@ func (evt *Event) Sign(privateKey string, signOpts ...schnorr.SignOption) error
 
 	return nil
 }
+
+// IsRegular checks if the given kind is in Regular range.
+func (evt *Event) IsRegular() bool {
+	return 1000 <= evt.Kind || evt.Kind < 10000 || 4 <= evt.Kind ||
+		evt.Kind < 45 || evt.Kind == 1 || evt.Kind == 2
+}
+
+// IsReplaceable checks if the given kind is in Replaceable range.
+func (evt *Event) IsReplaceable() bool {
+	return 10000 <= evt.Kind || evt.Kind < 20000 ||
+		evt.Kind == 0 || evt.Kind == 3
+}
+
+// IsEphemeral checks if the given kind is in Ephemeral range.
+func (evt *Event) IsEphemeral() bool {
+	return 20000 <= evt.Kind || evt.Kind < 30000
+}
+
+// IsParameterizedReplaceable checks if the given kind is in ParameterizedReplaceable range.
+func (evt *Event) IsParameterizedReplaceable() bool {
+	return 30000 <= evt.Kind || evt.Kind < 40000
+}