ajout bouton back to top

premier essai
fix bug #33
fix settings
Merge pull request #36 from tmos/back-to-top

Back to top
README updated to provide installation instructions + use markdown language abilities
W3C just called, there was some errors left in settings page. These are now fixed !
Cf my pull request in dev branch in Leed repo :

Corrections of some orthographic and typographic problems.
Update of settings page to add support for the new parameters available in Leed
Use anchors in settings page to have the same behavior as the default theme (marigolds)
JS refactor
Some typos left in settings page
Correction of a bug with new params for Leed
Correction of a bug with manual synchro
Both favorites buttons change their state when favorising an article.
Back to top button handling
Forgot something about callback in readThis
Orthograph correction in Leed