I am publishinga Nuget package in incrementally iterative and highly-frequent mode.
What is the best place to put the change-log? Is it the [Description].
Or is there a specific place to put the change-log in a reverse chronological order?
I would eventually push this package to [ProGet] too...and if there is any practice around it regarding change-log?
You can put this value in the <releaseNotes> element (from the NuGet .nuspec reference):
A description of the changes made in each release of the package. This field only shows up when the Updates tab is selected and the package is an update to a previously installed package. It is displayed where the Description would normally be displayed.
Since this is interpreted by the NuGet client and not the server, the ProGet handling is the same.