update promql-to-scrape README (#102)

* update promql-to-scrape README

Update to more accurately reflect the guidance we give for users of
this service.

* clarify time delay

https://github.com/temporalio/samples-server/blob/main/cloud/observability/promql-to-scrape/internal/client.go#L88

* remove confusion

Author: TimSimmons

cloud/observability/promql-to-scrape/README.md

@@ -21,9 +21,9 @@ This means you can now hit http://localhost:9001/metrics on your machine and see
 
 ### Important Usability Information
 
-**Important:** When you go to scrape this, you should do so with a **60s** scrape interval, unless you are meaningfully modifying this code. The example queries all assume a 1 minute rate and you'll want these to be equal.
+**Very Important:** This application will show data _delayed by one minute_. This is done in an attempt to smooth out some aggregation delay. However, you may encounter issues with data appearing missing if you **use a rate interval < 2m**.
 
-**Very Important:** The data you will see here is approximately 1 minute delayed (should you conform to the guidance above). Due to the aggregation that happens before metrics are presented to you, it's necessary for us to send the queries from this application to look 60 seconds in the past. Otherwise data aggregation would not be complete, and there would be no results for each query.
+**Important:** When you scrape this endpoint, you should do so with a scrape interval **<= the rate interval of the queries in your config file, and at least 1m**.
 
 ## Deployment