Add ElasticSearch query examples

api/internal/crawl/search_cmds/defaultBranch.md

@@ -0,0 +1,32 @@
+Count distinct values of the `defaultBranch` field:
+```
+curl -X POST "${ElasticSearchURL}:9200/kustomize/_search?size=0&pretty" -H 'Content-Type: application/json' -d'
+{
+    "aggs" : {
+        "defaultBranch_count" : {
+            "cardinality" : {
+                "field" : "defaultBranch",
+                "precision_threshold": 40000
+            }
+        }
+    }
+}
+'
+```
+
+List all the github branches where kustomization files and kustomize resource files live, 
+and how many kustomization files and kustomize resource files live in each branch:
+```
+curl -X GET "${ElasticSearchURL}:9200/kustomize/_search?pretty" -H 'Content-Type: application/json' -d'
+{
+    "aggs" : {
+        "defaultBranch" : {
+            "terms" : {
+              "field" : "defaultBranch",
+              "size": 41
+            }
+        }
+    }
+}
+'
+```