Additional options: use-attributes and table-config-path

[cmungall]

This provides two new options

  -C, --table-config-path TEXT    YAML file with header mappings
 -A, --use-attributes, --no-A / --no-use-attributes
                                  All slots specified in conjunction with a
                                  class are attributes of that class
                                  [default: no-use-attributes]

Example: sheets2linkml tests/input/personinfo-no-descriptors.tsv -C tests/input/personinfo-descriptors.yaml