make router resources configurable (needed for router HPA setup) (#1857)

Co-authored-by: Daniel Candrea <daniel.candrea@complyadvantage.com>
Co-authored-by: Vishal <vishal-biyani@users.noreply.github.com>
Co-authored-by: Sanket Sudake <sanketsudake@gmail.com>

charts/fission-core/values.yaml

@@ -127,6 +127,16 @@ router:
   #  tolerations:
   #  nodeSelector:
 
+  # Pod resources as:
+  #  resources:
+  #    limits:
+  #      cpu: <tbd>
+  #      memory: <tbd>
+  #    requests:
+  #      cpu: <tbd>
+  #      memory: <tbd>
+  resources: {}
+
 ## Persist data to a persistent volume.
 persistence:
   ## If true, fission will create/use a Persistent Volume Claim unless storageType is set to s3