The HTML format can be transformed into a PDF document if you wish. You can do it in different ways. One of them is installing on your GNU / Linux distribution the HTMLDOC app. It is an app with a simple GUI, although you can also use it from the command line. It is cross-platform and open source, you can also see more details in its official website. To download the tarball with the source code that you can compile, you can go to your GitHub site.
You also have it available in many of the repositories of the most popular distros, so you can use the package manager for a simple installation from the binary. Once installed, you can start using it. Remember that it is not a web to PDF converter, but a HTML documents to PDF. And if you want to do the conversion, it would be as easy as running the following command:
htmldoc --webpage -f nombre.pdf nombre.html
If you do it from the GUI it is much simpler and more intuitive. Another thing is that you want convert web page to PDF. For example, imagine that you visit this blog and you like some of its articles. You want to keep it locally in a PDF to view it offline if you don't have a connection all the time or you just want to keep a copy in case it is deleted from the blog. For that there are other very good online tools like this:
Just copy the URL of the article or page that you liked, paste it in the box and press the button to generate the PDF that you can download for free and without registration. The only limit is the number of documents that you can convert in a month ... In addition to that tool, there are other options to do this that I comment, but this is my favorite for its simplicity and effectiveness. Although I have to say, that some web pages cannot convert them, but they are the minority ...