apply suggestions from code review

Co-Authored-By: Myles Borins <myles.borins@gmail.com>

README.md

@@ -542,8 +542,7 @@ maintaining the Node.js project.
 
 ### Release Keys
 
-GPG keys used to sign Node.js releases (you may encounter a release signed
-by a sub-key of a key listed below (which itself isn't listed below)):
+Primary GPG keys for Node.js Releasers (some Releasers sign with subkeys):
 
 * **Beth Griggs** <bethany.griggs@uk.ibm.com>
 `4ED778F539E3634C779C87C6D7062848A1AB005C`