Allow for importing render function

[gitkief]

dewret/src/dewret/__main__.py

Line 168 in 68ef970

render()

It would be nice to wrap the render call in a if __name__ == "__main__": block to allow to import and use the render function in other Python scripts and tests.

[edufnt]

This would be obsoleted by discussion: #70 , which is IMO a cleaner approach.

[gitkief]

Despite #70, I would still/in addition safe guard the render() function to allow unit testing the actual cli-interface.