docs: add multi-linear terms section to terms overview, explain de prefix
docs: add multi-linear terms section to terms overview, explain de prefix

rc/sfepy,sfepy/sfepy,BubuLK/sfepy,rc/sfepy,BubuLK/sfepy,sfepy/sfepy,vlukes/sfepy,vlukes/sfepy,sfepy/sfepy,vlukes/sfepy,BubuLK/sfepy,rc/sfepy