• add first draft
• docs
• add pydantic
• add async fetch
• add a function to get a single attribute for all elements
• update
• add semaphore and download path
• refactor fetch and save
• 🦆
• add migration to new schema for ionization energies
• extend the ionization energy model
• 💄
• update the alembic migration
• update docs for ionization energies
• data update for ionization energies
• refactor fetching and processing data

Proposed Changes

• Update the ionization energy from NIST ASD database
• Add utilities to fetch NIST ASD data easily mendeleev/interfaces/nist_asd.py
• Add mendeleev.get_attribute_for_all_elements convenience function and refactor tests