Ignore contact fields that are set to none (#16)

* Add optional contact info

Ignore contact fields that are set to none. 
Email is taken as the "priority" field which is most likely set and therefore doesn't have a separator field included. This could be either set to a different field or be replaced by a better function.

* Fix Expression error

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Co-authored-by: Paul T <developer.paul.123@gmail.com>

template/resume.typ

@@ -16,7 +16,7 @@
     ),
   ),
   date: datetime.today().display(),
-  colored-headers: true
+  colored-headers: true,
 )
 
 = Experience