Various typographical, spelling and grammar fixes.

In the course of reading your excellent primer (I'm new to CFE myself), the ghost of an old English teacher in the back of my head pointed out a few things; given that we're both on github, I decided to offer you fixes for them :-)
Two things I noticed but wasn't sure how to fix remain:

In slide 37: does using a regex to specify the processes trump the .* prefix-and-suffix that you mention ?
i.e. will "^bluetoothd" only match bluetoothd at start ?
If so - this would be worth mentioning !

In slide 41: make "CFEngine Reference Manual" a link !
I think I can see how to do that in this markup language, from the existing links, but I'm not sure which URL you'd use to refer to the reference manual.