Handle detecting license filetype

C4B requires a specifically named license file. We should add detection around this, and provide a friendly message in the console when a user drops a license file that is not named correctly into the license location.

Start by locating the license-file handling and console-message entry points, then review the C4B requirement for the specifically named license file. Done means an incorrectly named license file in the license location is detected and produces a friendly console message.

Written by the indexing model from the issue text.