Clarify aws4fetch usage in README

Author: mhart

README.md

@@ -4,9 +4,9 @@ aws4
 A small utility to sign vanilla Node.js http(s) request options using Amazon's
 [AWS Signature Version 4](https://docs.aws.amazon.com/general/latest/gr/signature-version-4.html).
 
-If you want to sign and send AWS requests in a browser, or an environment like [Cloudflare Workers](https://developers.cloudflare.com/workers/), then check out [aws4fetch](https://github.com/mhart/aws4fetch) – otherwise you can also bundle this library for use [in older browsers](./browser).
+If you want to sign and send AWS requests using [`fetch()`](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API), then check out [aws4fetch](https://github.com/mhart/aws4fetch) – otherwise you can also bundle this library for use [in older browsers](./browser).
 
-The only AWS service that *doesn't* support v4 as of 2020-05-22 is
+The only AWS service I know of that *doesn't* support v4 is
 [SimpleDB](https://docs.aws.amazon.com/AmazonSimpleDB/latest/DeveloperGuide/SDB_API.html)
 (it only supports [AWS Signature Version 2](https://github.com/mhart/aws2)).