Fix missing reference link

Maruku isn't happy with trying to compile the site on my system due to the missing reference-style link here.
Add more link to blog posts.

I went looking for something on the site and this seemed like an omission in the design - it's logical to let people jump to more blog posts from the list of the last few...
Explain where to find HTML

Coming back to this fresh I spent a while figuring out how things go together/where to find elements. I've put these learnings into the README file to save time in the future.