Changes to the User Guide's Data Files page
Changes to the User Guide's Data Files page

  - All code snippets were given for `setup.py`. Have added
    corresponding snippets for `setup.cfg` and `pyproject.toml`.
  - To avoid incentivizing multiple top-level packages, have modified
    all the package trees and code snippets to include only a single
    package `mypkg`. Have added a separate example to illustrate the
    functionality of using the empty string `""` / the asterisk `*` for
    capturing data files from multiple packages. Have also modified the
    `setup.py` code snippets and removed the `find_packages("src")`
    since there is only a single package in each case (except one); have
    opted to explicitly name the package instead.
  - Have added a package tree example for the first `package_data`
    snippet. Have also added a package tree / code snippet example to
    show how `package_data` patterns should include subdirectories,
    separating it from the example showing the empty string `""` /
    asterisk `*` functionality.
  - Tried to have consistent naming for all directories and data files
    used in the package trees and code snippets. All directories have
    been named `mypkg` and data files have been named `data1.txt`,
    `data2.rst` etc.
  - Have reformatted package tree examples. Reformatting has been done
    by replacing the only-indentation based directory structure diagram
    with a line-based tree layout; I think this looks neater.
  - Have added `.. note::` blocks for paragraphs that would be more
    appropriately phased as a Note. Other minor changes to text content
    have been made.

pypa/setuptools,pypa/setuptools,pypa/setuptools