added description of coefficients list in output to docstring
added description of coefficients list in output to docstring

kaushik94/sympy,yashsharan/sympy,skidzo/sympy,postvakje/sympy,skidzo/sympy,jaimahajan1997/sympy,drufat/sympy,kaushik94/sympy,madan96/sympy,aktech/sympy,yashsharan/sympy,postvakje/sympy,jaimahajan1997/sympy,chaffra/sympy,souravsingh/sympy,jaimahajan1997/sympy,madan96/sympy,drufat/sympy,yashsharan/sympy,skidzo/sympy,madan96/sympy,sampadsaha5/sympy,chaffra/sympy,postvakje/sympy,drufat/sympy,kaushik94/sympy,souravsingh/sympy,aktech/sympy,sampadsaha5/sympy,sampadsaha5/sympy,aktech/sympy,chaffra/sympy,souravsingh/sympy