Update CENSUS.md

* Fix typo in `CONTRIBUTING.md` link
* Add Backports repositories maintainers list
* Add link to github's list of contributors as committers

CENSUS.md

@@ -1,4 +1,4 @@
-The project's census with roles as defined in (CONTRIBUTING.md)[CONTRIBUTING.md).
+The project's census with roles as defined in [CONTRIBUTING.md](CONTRIBUTING.md).
 
 ### Project Leads
 * Developer Advocate Lead
@@ -18,4 +18,14 @@ The project's census with roles as defined in (CONTRIBUTING.md)[CONTRIBUTING.md)
 * Espresso
   * [Alfonso Peterssen](https://github.com/mukel)
 
-### Committers
+### Backports Repositories Lead Maintainers
+
+* [GraalVM for JDK 21](https://github.com/graalvm/graalvm-community-jdk21u)
+  * [Foivos Zakkak](https://github.com/zakkak)
+
+* [GraalVM for JDK 17](https://github.com/graalvm/graalvm-for-jdk17-community-backports)
+  * None, please consider nominating yourself by sending an email to [graalvm-maintainers_ww_grp@oracle.com](mailto:graalvm-maintainers_ww_grp@oracle.com) as mentioned in https://github.com/oracle/graal/issues/8935
+
+### Committers
+
+See https://github.com/oracle/graal/graphs/contributors