Apply suggestions from code review
Apply suggestions from code review

Improvements to README

Co-Authored-By: astrofrog <5a30e73bb3eb7866ce4ccff234d7add82054e98d@gmail.com>
Cadair/astropy-helpers,astropy/astropy-helpers,astropy/astropy-helpers,Cadair/astropy-helpers,dpshelio/astropy-helpers,dpshelio/astropy-helpers