Make clear it's a csv being downloaded
Make clear it's a csv being downloaded

gds-attic/transactions-explorer,gds-attic/transactions-explorer,alphagov/transactions-explorer,alphagov/transactions-explorer,gds-attic/transactions-explorer,alphagov/transactions-explorer,gds-attic/transactions-explorer,gds-attic/transactions-explorer,alphagov/transactions-explorer,alphagov/transactions-explorer