better answer the ms word question - fixes #25

thanks @joanwolk
use inclusive language

thanks @joanwolk
Some typos & wording fixed
An extra warning and a very short paragraph on hierarchy
Switched to a better example and left out the "not like this" part, added a sentence about specifity
Merge pull request #28 from bastianalbers/gh-pages

Added a short note on hierarchy in the styles section and some typos fixed