feat(notifications): add json template

pkg/notifications/model.go

@@ -0,0 +1,19 @@
+package notifications
+
+import (
+	t "github.com/containrrr/watchtower/pkg/types"
+	log "github.com/sirupsen/logrus"
+)
+
+// StaticData is the part of the notification template data model set upon initialization
+type StaticData struct {
+	Title string
+	Host  string
+}
+
+// Data is the notification template data model
+type Data struct {
+	StaticData
+	Entries []*log.Entry
+	Report  t.Report
+}