Create changelog.md

Include a separate changelog to keep the readme more focused and smaller
Create contributing.md. closes #25

include separate contributing file to keep readme more focused and smaller
Update README.mdown - closes #26

add options and usage, remove contributing and changelog
add option to enable hb register helpers. closes #28
add doc for hbHelpers option. see #28
README.mdown: fix typo.

'containt' => 'contain'
Merge pull request #30 from tcort/typo

README.mdown: fix typo.
pre code preserves new lines and causes excessive spacing. CSS should handle that spacing instead
Merge pull request #31 from eddiemonge/precode

pre code preserves new lines and causes excessive spacing.
add section support