Update docs/manual_curation.md as suggested by @cyenyxe
Update docs/manual_curation.md as suggested by @cyenyxe

Co-Authored-By: Cristina Yenyxe Gonzalez Garcia <2755b6a31ffbe21a4156ea89e38b2a4d6686199c@ebi.ac.uk>
EBIvariation/eva-cttv-pipeline