Morph-kgc

This release features support for [Apache Kafka](https://kafka.apache.org/) which allows to materialize triples to a [Kafka](https://kafka.apache.org/) topic.

Changes
- 198: Support for [Apache Kafka](https://kafka.apache.org/) by LuciaCabanillasRodriguez.
- 199: sqlalchemy is now an optional dependency.
- 202: Bug in graph maps with YARRRML fixed.
- 214: Docs are now maintained in a separate repository (https://github.com/morph-kgc/morph-kgc-docs).
- 216: Test cases by kg-construct have been updated to their latest version.
- 218 219: Deprecation warnings fixed and upgrade of dependencies.
- 225: docker containerization by LuciaCabanillasRodriguez.

This is a bug fix release. There are no new features.

This release upgrades to [Pandas](https://github.com/pandas-dev/pandas) 2.0 and fixes YARRRML bugs.

Changes
- 147: Upgrade to [Pandas](https://github.com/pandas-dev/pandas) 2.0 and to [SQLAlchemy](https://github.com/sqlalchemy/sqlalchemy) 2.0.
- 181, 184: YARRRML bug fixes.
- 150: Allow geojson file extension.

This is a bug fix release. There are no new features.

This is a bug fix release. There are no new features.

Changes

- 176: processing function maps defined in the subjects of YARRRML mappings.
- 177: correct output for deeply nested star maps with multiple predicate-object maps.

This release features support for [YARRRML](https://w3id.org/kg-construct/yarrrml), a user-friendly serialization of RML (also for [RML-star](https://w3id.org/rml/star/spec) and [RML-FNML](https://w3id.org/rml/fnml/spec)). Compliance with [RML-Core](https://w3id.org/rml/core/spec) has also been implemented.

Changes
- 167: [YARRRML](https://w3id.org/kg-construct/yarrrml) support.
- 170: [RML-Core](https://w3id.org/rml/core/spec) compliance.
- 172: Upgrading to the latest version of [RML-FNML](https://w3id.org/rml/fnml/spec).
- 173: Bug fix for in-memory DataFrames with _NaN_ cells, by ershimen.