If considering implementing graphs: Graphviz, mermaid or flowchart.js all are good options and have implementations in js (many have implementations as React components).
Another alternative to not add parsing is http:asciiflow.com/
+--------+ +----------+ | +------> | | Hello! +------> | +--------+ +----------+
But sadly it breaks; possible because of the font.
And you can use this handy web page to generate GraphViz graphs in SVG form (which you can then link / embed).
If considering implementing graphs: Graphviz, mermaid or flowchart.js all are good options and have implementations in js (many have implementations as React components).
Another alternative to not add parsing is http:asciiflow.com/
+--------+ +----------+ | +------> | | Hello! +------> | +--------+ +----------+
But sadly it breaks; possible because of the font.
And you can use this handy web page to generate GraphViz graphs in SVG form (which you can then link / embed).