Sets primary and replica shard counts

Why are these changes being introduced:

* AWS uses a default of 5 which is larger than our current and predicted
  data size indicates is appropriate for any single index

Relevant ticket(s):

* https://mitlibraries.atlassian.net/browse/TIMX-187

How does this address that need:

* Sets the value of primary and replica shards to 1 for all indexes
  created via TIM by adding those values to our existing settings
  loader

Author: JPrevost

config/opensearch_mappings.json

@@ -1,5 +1,7 @@
 {
   "settings": {
+    "number_of_shards": 1,
+    "number_of_replicas": 1,
     "analysis": {
       "analyzer": {
         "keyword_no_trailing_punctuation": {
@@ -398,4 +400,4 @@
       }
     }
   }
-}
+}