vim:nvim: force write shada file on exit
vim:nvim: force write shada file on exit

deleting marks across sections are not preserved. nvim guys claim that
this is perfectly normal but ViM developers think otherwise. Hence force
write shada data to have behavioural sync between vim and nvim.

Signed-off-by: Ratheesh S <f847af0ee3590f4912d169b886f309989d9e4c2e@gmail.com>

ratheesh/dot-files,ratheesh/dot-files