Add a guide for adjusting airflow scheduler resources (#872)

Author: chrishronek

airflow/plural/docs/adjust-scheduler-resources.md

@@ -0,0 +1,36 @@
+## Adjusting Scheduler Resources
+
+In Airflow, the [scheduler](https://airflow.apache.org/docs/apache-airflow/stable/administration-and-deployment/scheduler.html) 
+monitors all tasks and DAGs, then triggers the task instances once their dependencies are complete.
+
+You may find that you need to increase the number of schedulers that you are running as well as increase the resources 
+available to each scheduler.
+
+### edit values.yaml
+
+In order to update scheduler resources, you'll then want to edit `airflow/helm/airflow/values.yaml` in your installation 
+repo. If you wanted 2 schedulers each with at least 0.5 cpu & 1.75Gi of resources, you'd make the following change:
+
+```yaml
+airflow:
+  airflow:
+    airflow:
+    scheduler:
+      replicas: 2
+      resources:
+        limits:
+          cpu: 1.5
+          memory: 2.5Gi
+        requests:
+          cpu: 0.5
+          memory: 1.75Gi
+```
+
+> It is highly recommended to set limits on your scheduler(s) to ensure fair resource sharing across your cluster.
+
+Alternatively, you should be able to do this in the configuration section for airflow in your plural console as well.
+
+### redeploy
+
+From there, you should be able to run `plural build --only airflow && plural deploy --commit "update scheduler 
+resources"` to adjust your Airflow scheduler configuration