schemasheets export functionality missing linkml column descriptors

[sujaypatil96]

Using the schemasheets functionality that exports a provided linkml schema to a schemasheets specific tsv file, based on a specification tsv file is incomplete. In that, it does not make the output tsv file with the second row containing linkml column descriptors as expected.

export_spec.tsv:

Class	Field	Description	Key	Range
>class	slot	description	identifier	range

Run the export command as follows:

linkml2sheets ~/path/to/export_spec.tsv -s tests/input/personinfo.yaml -o personinfo.tsv

See the output file missing the second row with linkml column descriptors.