Yes, poetry aims to completely obsolete the use of Manifest.in files. The assumption is, that every file that is part of your package should also be part of the distributable. So, as long as you follow a more or less standard project structure, things should Just Work™.
And if your package happens to be structured in a strange way, or you want to package files that for some reason aren’t in the source folder, you can use the include and exclude sections for that.
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