This is the way. This is how I do it with mine but use channels instead of flakes because I'm a giant curmudgeon.

My devshell can be found here and is dead simple: https://github.com/stusmall/stuartsmall.com/blob/main/defaul...

I used Zola for my SSG and can't think of the last breaking change I've hit. I just use the pattern of locked nix devshells for everything by default. The extra tools are used for processing images or cooklang files.