sig-contribex: add leads emails to sigs.yaml

Author: Priyankasaggu11929

sigs.yaml

@@ -1378,16 +1378,20 @@ sigs:
     - github: kaslin
       name: Kaslin Fields
       company: Google
+      email: [email protected]
     - github: palnabarun
       name: Nabarun Pal
       company: VMware
+      email: [email protected]
     tech_leads:
     - github: MadhavJivrajani
       name: Madhav Jivrajani
       company: VMware
+      email: [email protected]
     - github: Priyankasaggu11929
       name: Priyanka Saggu
       company: SUSE
+      email: [email protected]
     emeritus_leads:
     - github: Phillels
       name: Elsie Phillips