Need for Speed Updates

[arnavs]

In a future 2.0 release of the notes, we might consider updating this to include patterns we use in practice:

• A lot of the lecture is about writing structs, which is something we generally discourage people from doing.
• Could include the case of a problem involving some setup work and a repeatedly called kernel (i.e., when to use a function barrier, using inplace operations, etc.)
• Maybe a few words on GPU stuff for linear algebra (possibly in advanced.)
• Preallocation vs push!, broadcasting, array views, etc.