Updated all the .xml and .cd files

These files are the ones that were present in the website repo. Since they don't exist anymore in this repository, we took the most up to date ones for the cduce/web repo

@kn If you can take a look at make @website, it's raising a warning:

File "site.cd", line 427, characters 5-2453:
Warning: The capture variable right is declared in the pattern but not used in the body of this branch. It might be a misspelled or undeclared type or name (if it isn't, use _ instead).