x-Axis based on DateTime object and dots

Nobody has claimed this yet.

Firstly i must to say that a worked with a lot of Flutter's chart library, and this is the best i found!

I have a problem with two lines on the same graph, and after a lot of checks i found that the **x-Axis is based only on indexs, and can't be based on DateTime!**
in my case it's really a big problem, because i have 2 lines to show on the graph, one based on quarter of an hour, and the second on minute, in this case there is no match between the 2 lines and the x-Axis.
As you can see on the orange text, the km/h and the date is right, but the location on the graph is not

Google charts is support DateTime graph, in Time Series Charts
https://google.github.io/charts/flutter/gallery.html
You can also see, for example, the Weekly Chart the x-Axis is based on DateTime object
https://pub.dev/packages/bezier_chart

One more important thing is the **barWidth**, if is set to 0 the line is still appear, it could be good and right that 0 value make the line transparent, **and stay only the Dots to appear.**
In my case it's help to see a dangerous wind that more than 50km/h
(in the image attached i just drawed the red points in photoshop for the example, that why it's on 20kmh~)

**Hope you will fix and support this because it's really critical, and add values to your awesome graph.**

Start by reproducing the two-line chart with quarter-hour and minute DateTime data, then compare the x-axis placement with the attached examples. Check how barWidth set to 0 renders and verify that dots remain visible while the line disappears. Done means DateTime-based alignment and the requested zero-width behavior both work.

Written by the indexing model from the issue text.