HowToGenerateAPackage.md

How to generate a nuget package from a discovery doc

This isn't quite a simple as it could be, but it's fairly simple:

1. Use a Windows machine with Visual Studio 2022 v17.8 or greater; and a recent version of git.
2. git clone https://github.com/google/google-api-dotnet-client.git
3. Delete all files from the DiscoveryJson directory. They are all .json files.
4. Copy the discovery-doc json file into the DiscoveryJson directory.
5. Execute ./BuildGenerated.sh --skipdownload from within git bash.
6. The nuget package will be generated into nupkgs/generated/ directory.