Add Geo to Kushal's role

Summary

I've been working Geo frontend from time to time while being a stable counterpart for Plan team, but I realised this is not explicit in our handbook which may cause confusion for Geo team members as they may need frontend help but are not aware of who can take it up. I've discussed this earlier with @andr3 that I can easily manage FE tasks across both the sides as frontend work on Geo is not that frequent and I'm aware of entire frontend involved for Geo which only makes it easy for me to do any changes there.