Maintainers.md: Update and add users

Author: gursewak1997

MAINTAINERS.md

@@ -4,6 +4,8 @@ The current Maintainers Group for the bootc Project consists of:
 
 | Name              | GitHub ID                                                            | Employer        | Responsibilities |
 | ----              | ----                                                                 | ----            | ----             |
-| Chris Kyrouac     | [ckyrouac](https://github.com/orgs/containers/people/ckyrouac)       | Red Hat         | Approver         |
-| Colin Walters     | [cgwalters](https://github.com/orgs/containers/people/cgwalters)     | Red Hat         | Approver         |
-| John Eckersberg   | [jeckersb](https://github.com/orgs/containers/people/jeckersb)       | Red Hat         | Approver         |
+| Chris Kyrouac     | [ckyrouac](https://github.com/orgs/bootc-dev/people/ckyrouac)        | Red Hat         | Approver         |
+| Colin Walters     | [cgwalters](https://github.com/orgs/bootc-dev/people/cgwalters)      | Red Hat         | Approver         |
+| John Eckersberg   | [jeckersb](https://github.com/orgs/bootc-dev/people/jeckersb)        | Red Hat         | Approver         |
+| Gursewak Mangat   | [gurusewak](https://github.com/orgs/bootc-dev/people/gursewak1997)   | Red Hat         | Approver         |
+| Joseph Corchado   | [jeckersb](https://github.com/orgs/bootc-dev/people/jmarrero)        | Red Hat         | Approver         |