feat(unixode.sty): add subscript 1,2
feat(unixode.sty): add subscript 1,2

fpvandoorn/tutorial,leanprover/tutorial,soonhokong/lean-tutorial,soonhokong/lean-tutorial,fpvandoorn/tutorial,Hodapp87/cs6460_project,avigad/tutorial,avigad/tutorial,leanprover/tutorial,avigad/tutorial,leanprover/tutorial,cjmazey/fork_leanprover_tutorial,soonhokong/lean-tutorial,Hodapp87/cs6460_project,Hodapp87/cs6460_project,cjmazey/fork_leanprover_tutorial,cjmazey/fork_leanprover_tutorial,fpvandoorn/tutorial