WEB: Added <datafiles> nodes to link to wiki page

Added in the xml file another type of data to every game that contains the anchor part (after the '#') so that is possible to link every game in the compatibility page to the relative data files page in the wiki.

Example:

<datafiles>Blade_Runner</datafiles>

is for the link:

https://wiki.scummvm.org/index.php?title=Datafiles#Blade_Runner