Stable release with all data resouces

This release is the first stable release and contains all data assets.

Data files in parquet/json and csv are included. Use pip install from the unzipped package to install sdnist. Download SDNist-data-1.2.01 and run sdnist from the unzipped directory to prevent attempts to download the data from NIST servers.

SDNist-data-1.2.0.zip contains all data tables in parquet/json and csv.

Full Changelog: v0.1.2...v1.2.0