Fix typo in proposals/20200330-spot-instances.md

Author: 0x2b3bfa0

docs/proposals/20200330-spot-instances.md

@@ -137,7 +137,7 @@ the following requirements for integration will work for each of AWS, Azure and
 
 #### Story 1
 
-As an operator of a Management Cluster, I want to reduce costs were possible by leveraging cheaper nodes for interruptible workloads on my Workload Clusters.
+As an operator of a Management Cluster, I want to reduce costs where possible by leveraging cheaper nodes for interruptible workloads on my Workload Clusters.
 
 #### Story 2