Add docs on how to access decomposed units
Add docs on how to access decomposed units

saimn/astropy,lpsinger/astropy,mhvk/astropy,mhvk/astropy,lpsinger/astropy,pllim/astropy,StuartLittlefair/astropy,saimn/astropy,larrybradley/astropy,StuartLittlefair/astropy,StuartLittlefair/astropy,pllim/astropy,astropy/astropy,StuartLittlefair/astropy,pllim/astropy,StuartLittlefair/astropy,saimn/astropy,astropy/astropy,larrybradley/astropy,saimn/astropy,larrybradley/astropy,mhvk/astropy,pllim/astropy,astropy/astropy,larrybradley/astropy,pllim/astropy,larrybradley/astropy,astropy/astropy,saimn/astropy,astropy/astropy,lpsinger/astropy,mhvk/astropy,lpsinger/astropy,lpsinger/astropy,mhvk/astropy