fix docstring formatting of tensor_product()
fix docstring formatting of tensor_product()

vlukes/sfepy,lokik/sfepy,rc/sfepy,BubuLK/sfepy,RexFuzzle/sfepy,rc/sfepy,sfepy/sfepy,vlukes/sfepy,BubuLK/sfepy,vlukes/sfepy,rc/sfepy,RexFuzzle/sfepy,RexFuzzle/sfepy,lokik/sfepy,sfepy/sfepy,RexFuzzle/sfepy,BubuLK/sfepy,lokik/sfepy,lokik/sfepy,sfepy/sfepy