I followed the steps to create and publish a nuget package including a readme.txt. (https://docs.microsoft.com/en-us/nuget/quickstart/create-and-publish-a-package-using-visual-studio?tabs=netcore-cli)
The initial version of the readme.txt correctly opens when the package is installed. But, I made changes to the readme.txt, re-packed it, re-added it to my local nuget feed (I deleted the previous), and when I install it, it opens the initial version of the readme.txt. My changes are not in it.
The dates of the package are updated in both my bin\Release and C:\LocalNugetPackageFeed\packages.