The docstring in pygmt/src/grdclip.py needs a 'Returns' section.

To fix this issue, copy and paste L82-89 in pygmt/src/grdcut.py:

to add a returns section between L70 and L71 in pygmt/src/grdclip.py:

A local development environment is not needed to address this issue (no installation required) 🎉 Just follow these instructions for editing the documentation on GitHub: https://www.pygmt.org/dev/contributing.html#editing-the-documentation-on-github.