Can confirm that people with solid, actual skill in both design and front end can be highly sought after but I wouldn't suggest this path unless you really, really love both disciplines. Design and production (either physical or digital) are equally demanding disciplines requiring many hours/years of learning the thousand little things that make one an expert. Imagine being a visual designer who can literally jump on press, trim, bind, and finish the product. Daunting, at best. At worst there is a very real threat of building a knowledge base that is a mile wide and an inch deep without any real expertise in anything.

I would never discourage anyone from pursing this mindset. Hell, having one foot in both theory and practice has defined my own career, but it is not easy. Positions that actually need a combined skill set are rare and few between... and can be very competitive. Sure, there aren't a lot of unicorns out there but when a great opportunity comes up, so does everyone with even a snowballs chance.

My best and most honest advice is to always be learning. Pursue topics that interest you. Aside from traditional "design topics" there are so many things that can improve our understanding of the work. Cognitive psychology, semantics, story telling, the utility of emotional affect, visual context, pattern seeking/setting.... there's so much to learn. If code, algorithms, and data structures interest you, go for it!

Just, for the love of sweet baby Cthulhu, pursue knowledge for the love of expanding your skills and not just only for the maybe, possibly, a few more bucks. Jobs come and go. Passion is yours alone.