README: More consistent and readable white space

Mainly, this just separates paragraphs, so that the text is easier
on the eyes.

Signed-off-by: Michael Witten <mfwitten@gmail.com>
Acked-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>