Better documentation for when external interfaces are not found

[dgreene1]

Proposal:
Add a more clear message when tsoa can not find the interface that you're using.

Specifically, I'd like to recommend we change this:

throw new GenerateMetadataError(`No matching model found for referenced type ${typeName}.`);

to be:

throw new GenerateMetadataError(`No matching model found for referenced type ${typeName}. If ${typeName} comes from a dependency, please create an interface in your own code that has the same structure. Tsoa can not utilize interfaces from external dependencies.`);

Context:
It seems like a common challenge of adopting tsoa is the idea that the interfaces that you expose to your consumers should not change. Therefore tsoa does not allow you to use interfaces that are defined in dependencies. This has caused problems for a few users ( #340, #377, #334, and #205)