Update source/user_guide/creating.rst
Add a line mentioning the regex ^(?:[a-z][a-z0-9_]+/)*[a-z][a-z0-9_]+/?$ to the getting started documentation
Add a line mentioning the regex ^(?:[a-z][a-z0-9_]+/)*[a-z][a-z0-9_]+/?$ to the getting started documentation