Stacks intro (#60)
Stacks intro (#60)

* Initial edit for chapter

* Second pass over chapter

* Oz's comments

Bradfield/algos,Bradfield/algos,Bradfield/algos,Bradfield/algos,Bradfield/algorithms-and-data-structures,Bradfield/algorithms-and-data-structures,Bradfield/algorithms-and-data-structures,Bradfield/algorithms-and-data-structures