doc: add links to security steward companies

PR-URL: #52981
Reviewed-By: Ulises Gascón <ulisesgascongonzalez@gmail.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Paolo Insogna <paolo@cowtech.it>
Reviewed-By: Vinícius Lourenço Claro Cardoso <contact@viniciusl.com.br>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Rafael Gonzaga <rafael.nunu@hotmail.com>
Reviewed-By: Michael Dawson <midawson@redhat.com>

README.md

@@ -849,18 +849,18 @@ prioritize security releases. Security release stewards manage security
 releases on a rotation basis as outlined in the
 [security release process](./doc/contributing/security-release-process.md).
 
-* Datadog
+* [Datadog](https://www.datadoghq.com/)
   * [bengl](https://github.com/bengl) -
     **Bryan English** <<bryan@bryanenglish.com>> (he/him)
-* NodeSource
+* [NodeSource](https://nodesource.com/)
   * [juanarbol](https://github.com/juanarbol) -
     **Juan José Arboleda** <<soyjuanarbol@gmail.com>> (he/him)
   * [RafaelGSS](https://github.com/RafaelGSS) -
     **Rafael Gonzaga** <<rafael.nunu@hotmail.com>> (he/him)
-* Platformatic
+* [Platformatic](https://platformatic.dev/)
   * [mcollina](https://github.com/mcollina) -
     **Matteo Collina** <<matteo.collina@gmail.com>> (he/him)
-* Red Hat and IBM
+* [Red Hat](https://redhat.com) / [IBM](https://ibm.com)
   * [joesepi](https://github.com/joesepi) -
     **Joe Sepi** <<joesepi@ibm.com>> (he/him)
   * [mhdawson](https://github.com/mhdawson) -