feat(basics.org): Add new tutorial basics.
feat(basics.org): Add new tutorial basics.

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