review: correct requester pay information in README

Author: pjhartzell

README.md

@@ -1131,14 +1131,17 @@ Available aggregations are:
 ## Asset Proxy
 
 The Asset Proxy feature enables stac-server to proxy access to S3 assets through the STAC
-API by generating requester-pays pre-signed URLs. Only assets with S3 URIs (`s3://`
-prefix) are proxied; other URL schemes are ignored. When the Asset Proxy feature is
-enabled, asset `href` values pointing to S3 are replaced with proxy endpoint URLs when an
-Item or Collection is served, while the original S3 URLs are preserved in the
-`alternate.s3.href` field using the [Alternate Assets
-Extension](https://github.com/stac-extensions/alternate-assets). Subsequent GET requests
-to the proxy endpoint URLs are redirected to pre-signed S3 object URLS for download (the
-requester pays for S3 egress).
+API by generating pre-signed URLs. Only assets with S3 URIs (`s3://` prefix) are proxied;
+other URL schemes are ignored. When the Asset Proxy feature is enabled, asset `href`
+values pointing to S3 are replaced with proxy endpoint URLs when an Item or Collection is
+served, while the original S3 URLs are preserved in the `alternate.s3.href` field using
+the [Alternate Assets Extension](https://github.com/stac-extensions/alternate-assets).
+Subsequent GET requests to the proxy endpoint URLs are redirected to pre-signed S3 URLS
+for download. Note that the AWS account that stac-server is running under must have
+permission to access the S3 buckets containing the assets and that the stac-server AWS
+account will be charged for the S3 egress, regardless of whether the bucket is a
+"Requester Pays" bucket or not (the stac-server AWS account is the requester when
+generating the pre-signed URL).
 
 ### Configuration