Enhance project functionality: add email template, implement email sending, and improve table management routes

Also add qr code generation route

The table management in the database does currently not work

src/main.go

@@ -82,6 +82,7 @@ func main() {
 	r.GET("/login", getLogin)
 	r.POST("/login", postLogin)
 	r.GET("/magic", getMagic)
+	r.GET("/qr/:qrSlug", getQr)
 
 	authorized := r.Group("/")
 	authorized.Use(RequireAuthMiddleware())