czso 0.2.3

Fixes responding to CRAN feedback

• Description field of DESCRIPTION now contains a link to the data provider
• documentation in all functions now provide more detail on what the functions return

Other changes

• czso_get_table_schema() now throws error for non-JSON schema and includes URL in error message
• czso_get_table() now writes files it cannot read with the right extension
• czso_get_dataset_doc() returns URL only invisibly if action is "open"