Added NuGet package readme files

[zhaparoff]

Motivation

Provide readme for NuGet packages.

Description of Changes

Added content to packages readme files

Checklist

• Acknowledged that contribution is made under the project's LICENSE
• Confirmed that PR and code/documentation changes are following the Contributor Code of Conduct
• PR is properly titled and contains the summary of changes introduced
• PR branch is based on the latest main branch commit
• PR contains some meaningful changes, including, but not limited to: functionality, tests, documentation, spelling, etc.
• Added/updated XMLDoc and inline comments in the code, according to the changes made
• Added/updated unit tests for added/changed functionality (if any)
• Added/updated documentation files (if applicable)