Fix tel links in README.md.

Author: bgaillard

README.md

@@ -54,4 +54,4 @@ you like to start your next project with us? That's great! Give us a call or sen
 you as soon as possible !
 
 You can contact us by email at [[email protected]](mailto:[email protected]) or by phone number 
-[(+33)6 85 12 81 26](+33685128126) or [(+33) 6 28 35 04 49](+33685128126).
+[(+33)6 85 12 81 26](tel:+33685128126) or [(+33) 6 28 35 04 49](tel:+33685128126).