The charts you linked don't look like the same kind of chart to me. There's information about what happened after what, but the information about how much each task took seems missing.

Mermaid Gannt[0] diagram type might be similar to what you have in mind.

[0] https://mermaid.js.org/syntax/gantt.html

i was using mermaid for this for years, but markwhen just seems/feels instantly easier.