Adding search not working

Many thanks for the great theme. 
i have tried to implement this gist https://gist.github.com/eddiewebb/735feb48f50f0ddd65ae5606a1cb41ae 
to get search working. 
https://kashifjournal.netlify.com/search/?s=markdown  this gives a blank page while it should return a search result. 
my repo https://github.com/Ammar-K/journal