v.1.2.0

• Add nlp_utilities.validators with validate_features and validate_xpos.
• Add converters/xpos/format_xpos to normalize various XPOS formats to Perseus.
• Refactor nlp_utilities.normalizers: replace old APIs with normalize_morphology(upos, xpos, feats, feature_set, ref_features=None) (breaking change).
• Update nlp_utilities/data/dalme_features.json (expanded VerbType and Case).
• Add docs/source/api_reference/validators.rst.
• Other improvements to documentation.
• Misc. bug fixes.
• Test-suite expansion: new/updated tests covering validators, formatters, converters, and normalizers.

Note: callers of the old normalize_features/normalize_xpos must be updated to the new API.

Full Changelog: v1.1.0...v1.2.0