make a mermaid chart online or gitlab has it built in markdown mermaid charts
but you can install it on a computer, which can be a pain, on my pixelbook i'm setup to create mermaid charts
graph lr
hinduism-->buddhism
buddhism-->vajrayana
buddhism-->theravada
taoism-->zen
buddhism-->zen
use vscode extension https://marketplace.visualstudio.com/items?itemName=tomoyukim.vscode-mermaid-editor
you can embed svg https://vecta.io/blog/best-way-to-embed-svg
this is an example using an svg file, updates to it will be on the buddhism site, you can also create png files
https://github.com/mermaid-js/mermaid-cli
2020-10-23 installed cli on pixelbook debian
sudo apt search yarn
sudo apt install yarnpkg
which yarn
apropos yarn
yarnpkg add mermaid.cli
./node_modules/.bin/mmdc -h
gitlab renders these for you, i have not played with it yet