Add up-to-date and up to date to the forbidden words

Resolve issue #436

doc.zih.tu-dresden.de/util/grep-forbidden-patterns.sh

@@ -34,6 +34,9 @@ i	hpc[ -]\+da\>
 \"ATTACHURL\" was a keyword in the old wiki, don't use it.
 
 i	attachurl
+Do not use \"up-to-date\", because this should be an inherent property of this great documentation.
+
+i \(\<up-to-date\>\|up to date\)
 Replace \"todo\" with real content.
 doc.zih.tu-dresden.de/docs/archive/system_triton.md
 i	\<todo\>	<!--.*todo.*-->