[Feature]: Moving milestone and task in timeline up and down with up and down button & Timeline view

[gozen-chama]

What is your set up?

Self Hosted Server

Is your feature request related to a problem? Please describe

Hi, its really great with leantime feature so far. In the timeline page (which is working like Gantt chart) milestone and task could be dragged with mouse which is good. But I'm facing a problem that when we drag it up and down, its really tricky as the time that we already set could be slightly move too. And there are some task that I add later to the milestone but they show up at the top of the milestone instead of below the milestone in the timeline page.

Describe the solution you'd like

So if there is a button to move the task and milestone up and down without changing the time that I already set it would be great. And its even better if you could make the task under the milestone stay visually under the milestone. Thank you.

Additional context

No response