cosmetic: minor documentation update

README.md

 
 The easiest way to test Tracim is to test it through the online demo:
 
-* [http://demo.tracim.org](http://demo.tracim.org)
+* [http://sandbox.tracim.org](http://sandbox.tracim.org)
 * login as admin: admin@admin.admin
 * password: admin@admin.admin
 
 
 # Support and Community #
 
-## Need help ? ##
-
 Building the community is a work in progress.
 
-Do not hesitate to contact me : damien.accorsi@free.fr
+Need help ? Do not hesitate to contact me : damien.accorsi@free.fr