FAQ: line breaks, and a handful of very minor corrections
Add AsciiDoc line breaks that were overlooked in d89e8fd3d4.
Remove superfluous line breaks.
Three points of grammar:
- mistakes (plural)
- avoid beginning a paragraph with the word 'And'
- mid-sentence, following a quote, 'some' (lowercase s).
Fixes: d89e8fd3d4 FAQ: TRIM: GELI, ZFS, OpenZFS: pruning, tidiness
Differential revision: https://reviews.freebsd.org/D37598