This link How do I create an XML Intellisense file for my DLL? explains how to build your dlls so that an XML file is included containing all your documentation headers so that they are available in those IntelliSense popups.
In my company we frequently distribute our own dlls using an internal NuGet package source. When I create NuGet packages for the package source, how do I ensure that someone else gets the dll from the package source, IntelliSense displays the documentation headers for them?