style(HACKING): Add notes about whitespace, naming, and wrapping

This patch is all about optimizing our coding style around readibility:

* Developers spend more time reading code than writing it.
* Newcomers have little (or no) context to draw upon when trying to understand the intent of the original author.
* Code is easier to reason about when it is self-documenting.

Change-Id: If7428195aa31104f194cb240faf5c6946d068e8d
Merge "style(HACKING): Add notes about whitespace, naming, and wrapping"