Improve documentation on baselines

Gantt
#1

I want to add baselines and ended up doing a deep dive into the code.

Turns out that it is possible to specify a className property on baseline that will be picked up. This is not documented.

Looking further there is actually no documentation on how to specify baselines at all except for the sample I think. Did I miss something or is it really missing?

#2

Hello,

Thank you for pointing out the undocumented className property — we’ll add it in the future.

At the moment, detailed information about built-in baselines can be found here:
https://docs.dhtmlx.com/gantt/desktop__inbuilt_baselines.html#baselines

For custom baselines, see this article:
https://docs.dhtmlx.com/gantt/desktop__baselines.html