Update readme for alert with Form

[zafercuz]

Updated readme when dealing with Form, as DialogButton outside content would result in having the Form validators not working.

[ibrahimdevs]

@zafercuz thanks for your feedback. Can you also add the example form please? I think, full working form example will be much better.

[ibrahimdevs]

@zafercuz I'm waiting for your contribution. Can you add an example to our project? It will be very helpful for other developers.

[bynalab]

Hi @ibrahimdevs, Can you please check the PR list? It has some changes you could merge.

[ibrahimdevs]

There is no reply for working example, I'm closing this PR for now.