Hi. The source code for Nenrikido is available on Github here: https://github.com/js044/nenrikido. In short, I use Hugo as my static site generator and Muuri (JS library) to control the layout. I'm not sure the best way to go about recreating functionality like RSS feeds/aggregators, but a webpage of simple bookmarks and widgets seems quite doable.
of course, i'm glad it was useful to you! it's such a good primer. been revisiting it a lot for grad school *_*