feat: initial commit

internal/mailer/mailer.go

@@ -0,0 +1,16 @@
+package mailer
+
+import "embed"
+
+const (
+	FromName            = "LK API"
+	maxRetries          = 3
+	UserWelcomeTemplate = "user_activation.tmpl"
+)
+
+//go:embed "templates"
+var FS embed.FS
+
+type Client interface {
+	Send(templateFile, username, email string, data any, isDevEnv bool) (int, error)
+}