Update link for obtaining product ID (#180)

old link leads to 404
also update ZKA -> DK, fix typo

Author: adnidor

docs/quickstart.rst

@@ -4,14 +4,14 @@ Getting started
 Register for a product ID
 -------------------------
 
-As of September 14th, 2019, all FinTS client programs need to be registered with the ZKA.
+As of September 14th, 2019, all FinTS client programs need to be registered with the Deutsche Kreditwirtschaft.
 You need to fill out a PDF form and will be assigned a product ID that you can pass to this library.
 It can take up to two weeks for the product ID to be assigned.
 
 The reason for this requirement is compliance with the European Unions 2nd Payment Services Directive (PSD2)
 which mandates that end-users can transparently see which applications are accessing their bank account.
 
-You cna find more information as well as the registration form on the `ZKA Website`_ (only available in German).
+You can find more information as well as the registration form on the `DK Website`_ (only available in German).
 
 Start coding
 ------------
@@ -64,4 +64,4 @@ commands using the client instance:
 
 Go on to the next pages to find out what commands are supported! There is also a full example on how to get your bank transactions if a TAN is required (:ref:`tans-full-example`).
 
-.. _ZKA Website: https://www.hbci-zka.de/register/prod_register.htm
+.. _DK Website: https://www.fints.org/de/hersteller/produktregistrierung