added docstrings to extension properties
added docstrings to extension properties
sdss/marvin,sdss/marvin,albireox/marvin,albireox/marvin,bretthandrews/marvin,bretthandrews/marvin,albireox/marvin,sdss/marvin,albireox/marvin,bretthandrews/marvin,bretthandrews/marvin,sdss/marvin