Minor docstring edits
Minor docstring edits

Co-authored-by: Eero Vaher <17cf8c99e6676a0316d383272ff82e2d3f1dbd49@gmail.com>
mhvk/astropy,mhvk/astropy,larrybradley/astropy,astropy/astropy,mhvk/astropy,pllim/astropy,astropy/astropy,StuartLittlefair/astropy,astropy/astropy,pllim/astropy,astropy/astropy,mhvk/astropy,larrybradley/astropy,larrybradley/astropy,StuartLittlefair/astropy,lpsinger/astropy,StuartLittlefair/astropy,mhvk/astropy,pllim/astropy,pllim/astropy,astropy/astropy,larrybradley/astropy,lpsinger/astropy,StuartLittlefair/astropy,StuartLittlefair/astropy,pllim/astropy,lpsinger/astropy,lpsinger/astropy,lpsinger/astropy,larrybradley/astropy