Update barbora-queues.md, karolina-queues.md, resources-allocation-policy.md - Add warning

docs.it4i/general/barbora-queues.md

+!!!Warning
+    This page has not been fully updated yet. The page does not reflect the transition from PBS to Slurm.
+
 # Barbora Queues
 
 Below is the list of queues available on the Barbora cluster:

docs.it4i/general/karolina-queues.md

+!!!Warning
+    This page has not been fully updated yet. The page does not reflect the transition from PBS to Slurm.
+
 # Karolina Queues
 
 Below is the list of queues available on the Karolina cluster:

docs.it4i/general/resources-allocation-policy.md

+!!!Warning
+    This page has not been fully updated yet. The page does not reflect the transition from PBS to Slurm.
+
 # Resource Allocation Policy
 
 ## Job Queue Policies