roles/council-advisor: Swap @jflory7 with @siddharthvipul1
    
    This commit updates the documentation for who the current Fedora D&I
    Council Advisor is. I was thinking to leave it blank, but since I know a
    bit about Vipul, I put a placeholder introduction that he can then
    follow up with any changes or modifications in a separate Pull Request.
    
    All the best @siddharthvipul1 on the new role, you have our confidence!
    
    Signed-off-by: Justin W. Flory (he/him) [Fedora Project] <jwf@fedoraproject.org>