Add Sourcegraph Analytics export API date filter options (#1193)

Add Sourcegraph Analytics export API date filter options

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Author: dadlerj

docs/analytics/cloud.mdx

@@ -153,3 +153,16 @@ export GRANULARITY="<GRANULARITY>"
 curl -X GET "https://analytics.sourcegraph.com/api/reports/by-user-client-date?instanceURL=$INSTANCE_URL&granularity=$GRANULARITY" \
  -H "Authorization: Bearer $ACCESS_TOKEN"
 ```
+
+Optional `startDate` and `endDate` values (formatted as `YYYY-MM-DD`) can be specified. Both parameters are optional. If neither is specified, the default is all time. If only one is specified, then only the start or end date filter will be applied.
+
+Example:
+
+```sh
+export INSTANCE_URL="<INSTANCE_URL>" # e.g. example.sourcegraphcloud.com
+export START_DATE="2025-01-01"
+export END_DATE="2025-12-31"
+
+curl -X GET "https://analytics.sourcegraph.com/api/reports/by-user-client-date?instanceURL=$INSTANCE_URL&startDate=$START_DATE&endDate=$END_DATE" \
+ -H "Authorization: Bearer $ACCESS_TOKEN"
+```