If I write Cargo.toml like this:

workspace
members = [
    "project_1",
    "project_2",
    "project_3/*",

And the project_3 have some directories and files, then the cargo build will be error.
Sometimes I wish to place readme.md in project_3 directory, at the sometime I want to write Cargo.toml with "*", then this problem occurs.
I think the cargo should know the readme.md is a file instead of directory, and the error above shouldn't occur.
Wish rust to be better.