moved assay metadata data to studies, removed assay

assays/leaf_sampling/README.md

assays/leaf_sampling/dataset/.gitkeep

assays/leaf_sampling/isa.assay.xlsx

assays/leaf_sampling/protocols/.gitkeep

assays/leaf_sampling/protocols/leaf_sampling.md

isa.investigation.xlsx

...es/gene_expression_eam7_plants_development/isa.study.xlsx

...protocols/development_plant_material_growth_conditions.md

studies/gene_expression_eam7_plants_diurnal/isa.study.xlsx

...nal/protocols/diurnal_plant_material_growth_conditions.md

studies/gene_expression_lwd1_mutants_diurnal/README.md

studies/gene_expression_lwd1_mutants_diurnal/isa.study.xlsx

...nal/protocols/diurnal_plant_material_growth_conditions.md