fix(10): add code tags
fix(10): add code tags

Otherwise, comm_semigroup looks like comm with a subscript semigroup.
soonhokong/lean-tutorial,avigad/tutorial,fpvandoorn/tutorial,Hodapp87/cs6460_project,soonhokong/lean-tutorial,Hodapp87/cs6460_project,leanprover/tutorial,leanprover/tutorial,leanprover/tutorial,soonhokong/lean-tutorial,fpvandoorn/tutorial,fpvandoorn/tutorial,avigad/tutorial,avigad/tutorial,Hodapp87/cs6460_project