apicompat --package-assembly-references is difficult to use

[ericstj]

The docs/usage say it should be TFM=file,file, but it's actually a tfm|file,file.

The docs don't indicate how to specify more than one TFM - but this is done by passing the parameter multiple times.

The docs say TFM but it actually needs the full form of the moniker. It should allow the short form (by parsing it).

The docs should also indicate that a directory works.

Alternate option for a package - generate a multi-targeting project for all frameworks discovered in package, add a reference to the package, restore it, and then drive API compat off such a project. This could save a lot of manual inputs, but it would be a lot to juggle (MSBuild reference, temporary project, etc etc).

[dotnet-policy-service]

@dotnet/area-infrastructure-libraries a new issue has been filed in the ApiCompat area, please triage