Most of the new IDE's for Coding including Vibe Coding can use Mermaid in your readme's and other markdown files.
This is my README,md (yes I put a comma in there instead of a . so it wouldn't put a dead link) from one of my new apps. You will notice that it has flowcharts built into it which make it very readable. The AI put those in because I just asked it to add mermaid diagrams and flowcharts to it. I also asked it to put in a Table of Contents.
It also makes it easier for others to understand the code and since AI wrote the code for me to understand it.