I've been using https://structurizr.com/ to automatically generate C4 diagrams from a model (rather than drawing them by hand). It works well with the approach for written documentation as proposed in https://arc42.org/. It's very easy to embed a C4 diagram into a markdown document.
The result is a set of documents and diagrams under version control that can be rendered using the structurizr documentation server (for interactive diagrams and indexed search).
I also use https://d2lang.com/ for declarative diagrams in addition to C4, e.g., sequence diagrams and https://adr.github.io/ for architectural decision records. These are also well integrated into structurizr.
The result is a set of documents and diagrams under version control that can be rendered using the structurizr documentation server (for interactive diagrams and indexed search).
I also use https://d2lang.com/ for declarative diagrams in addition to C4, e.g., sequence diagrams and https://adr.github.io/ for architectural decision records. These are also well integrated into structurizr.