docs: Quick formatting fixes

Doc used curly quotes in some code snippets; replaced with straight
quotes. Also removed trailing spaces and made a couple of other
formatting fixes.

I'll build the docs then go ahead and submit them. (See first comment
for doc stage location.)

bug: 25461271
Change-Id: I6a8df8d77ccbe1f17c3fe82e23d8c6623e6e0507