Q:

What are some secondary texts, in the form of online articles, to read about Kant's Prolegomena to Any Future Metaphysics?

What are some secondary texts, in the form of online articles, to read about Kant's Prolegomena to Any Future Metaphysics before I jump into the text and to ease myself into understanding it?
It would be preferable these web articles were written by Kant scholars and could be finished in around ~15 minutes.

I'm using the translation by Paul Carus as the Prolegomena, if that is of any relevance.
This is the version:--
(https://www.amazon.com/Kants-Prolegomena-any-Future-Metaphysics-ebook/dp/B004UO69DE/ref=sr_1_1?ie=UTF8&qid=1525052190&sr=8-1&keywords=1420938266)
Citation for the link above:--

Kant, Immanuel. Kant's Prolegomena to any future metaphysics. No. 53. Open court publishing Company, 1912.

A:

1) Not an article but there's a YouTube talk on the Prolegomena which might get you launched : 
https://www.youtube.com/watch?v=tEAqr_8PJqI
2) http://www.sparknotes.com/philosophy/prolegomena/section4/
It is worth a browse.
3) https://www.gradesaver.com/prolegomena-to-any-future-metaphysics/study-guide/summary-preamble
It is pretty basic but useful.

