#1316 Update packaging-projects.rst with a tip on good module naming

source/tutorials/packaging-projects.rst

@@ -538,7 +538,38 @@ some things you can do:
 * Read :pep:`517` and :pep:`518` for background and details on build tool configuration.
 * Read about :doc:`/guides/packaging-binary-extensions`.
 
+.. tip::
+
+   Make sure to have a valid `Python identifier`_ for your module name.
+   The PyPI project/dist name and the Python module may differ slightly.
+   For example, your package in pyproject.toml and on PyPI may have the name abcd-1234.
+   But a module named abcd-1234 would be cumbersome to import in Python,
+   since it isn't a valid identifier.
+   (There is a way to import it anyway, see importlib_ and this question_.)
+
+   .. code-block:: python
+
+      >>> import abcd-1234
+      >>> from abcd-1234 import something
+
+   would not work.
+   But having a directory structure with src/abcd_1234/ instead of src/abcd-1234/ has 2 consequences:
+
+   - The following works:
+
+     .. code-block:: python
+
+        >>> import abcd_1234
+        >>> from abcd_1234 import something
+
+   - Hatch will recognize that the module corresponding to the package is abcd_1234 instead of defaulting to src and building a not working wheel.
+   More information about `Python imports`_ and its grammar_.
 
+.. _Python identifier: https://docs.python.org/3/reference/lexical_analysis.html#identifiers
+.. _importlib: https://docs.python.org/3/library/importlib.html
+.. _question: https://stackoverflow.com/questions/8350853/how-to-import-module-when-module-name-has-a-dash-or-hyphen-in-it
+.. _Python imports: https://docs.python.org/3/reference/import.html
+.. _grammar: https://docs.python.org/3/reference/grammar.html
 ----
 
 .. rubric:: Notes