added registration form

index.md

@@ -49,7 +49,7 @@ Due to capacity constraints at the venue of the workshop, we kindly ask all part
 
 Use the following button to register. Registration will close on Friday, February 7.
 
-<a href="javascript:void(0)" type="button" class="btn btn-primary d-lg-inline-block my-lg-0 disabled" target="[blank](https://forms.office.com/e/P4ikS0FxaN)" enabled>Click here to register for the workshop</a>
+<a href="https://forms.office.com/e/P4ikS0FxaN" type="button" class="btn btn-primary d-lg-inline-block my-lg-0 disabled" target="_blank" enabled>Click here to register for the workshop</a>
 
 **Your registration will be completed only after you receive a confirmation email from the organizers.**