When packing or unpacking a solution with the Solution Packager, a MappingFile.xml is used to map files that are built (e.g. plug-in assemblies or web resources) to the corresponding files in the solution. Solution *.cdsproj projects generated by the Power Apps CLI (e.g. using pac solution init) run the Solution Packager automatically.
The files in this folder will allow solutions to be versioned independently as part of the build based on Git commits and/or Git tags. To make use of this sample, move Directory.Build.props, Directory.Build.targets, and Get-GitVersionSolutionVersion.ps1 into a folder where all of your *.cdsproj solution projects are descendants. For example, src/solutions/Directory.Build.props (where your solution projects are nested under src/solutions).
If you are already using a Directory.Build.targets and/or Directory.Build.props, copy the contents of these files into your files instead.