ENH: New FileTree method, just a convenience to get all short names

fsl/utils/filetree/filetree.py

@@ -58,6 +58,11 @@ class FileTree(object):
         res.update(self.variables)
         return res
 
+    @property
+    def short_names(self) -> List[str]:
+        """Returns a list containing all short names in the file tree. """
+        return list(self.templates.keys())
+
     def get_variable(self, name: str, default=None) -> str:
         """
         Gets a variable used to fill out the template