[enhancement] Allow custom templates

[anisalibegic]

One cool feature would be an option to define your own custom flash template, with your own HTML and etc. I could create a PR on this.

[lurumad]

Hi @anisalibegic

Could you create a PR?

Kind regards!

[riverahugo]

public IActionResult YourAction() { f.Flash(Types.Success, "Flash message system for ASP.NET MVC Core", dismissable: true); f.Flash(Types.Danger, "Flash message system for ASP.NET MVC Core", dismissable: false); return RedirectToAction("AnotherAction"); }

this not working -_-