Update README.md

Added link to zurb foundation project on drupal.org
Update README.md

Add comma for appositive phrase and corrected markdown.
Fix dropdown positioning when close to the right edge of the screen
Fix dropdown positioning for split buttons
Fix programmatic firing of reveal modals.
Merge branch 'master' of github.com:zurb/foundation
Fix issue with reveal background not injecting properly on pages with turbolinks.
Fix typo in Section documentation.
Update javascript to support auto tabs.
Merge conflicts.
updated sections for 'auto' styling
Update section.js to use data-section values instead of classes.
Update documentation to reflect section.js updates.
Populate the class options ul on the section documentation.
Merge pull request #1938 from magnolia-fan/fix_dropdown_positioning

Fix dropdown positioning when close to the right edge of the screen
Updates to dropdown right alignment.
bumped version to 4.0.9 and updated changelog
Update foundation.topbar.js
Merge pull request #1953 from Usse/patch-1

Update foundation.topbar.js issues 1915
fixed docs typo