Deployment in subfolder breaks calls to back-end

[nicowitteman]

In passwordless.login.js and passwordless.register.js, calls to back-end like "/pwmakeAssertion" don't work if the application is deployed in a subfolder like "https://somehost.com/myapplication/".
I suggest to
a) add this line to Login.cshtml and Register.cshtml:
<input type="hidden" id="BasePath" name="BasePath" value="@Url.Content("~")">
and
b) add a helper function like

function getFolder() {
    var dir = "";
    try {
        dir = document.getElementById('BasePath').value;
    } catch (e) {
    }
    return dir;
}

and then call
fetch(getFolder() + "/pwmakeAssertion" ....

[damienbod]

@nicowitteman Thanks for the feedback! Would you like to do a PR? If not I will update

Greetings Damien

[nicowitteman]

I prepared a PR, waiting for merge of #56