SPARKNLP 836 - Introducing "Instructor Embeddings" for sentence embeddings like Instructor-XL model

[prabod]

This PR adds Instructor embeddings to SparkNLP

Instructor-XL is the best model according to this leaderboard: https://huggingface.co/spaces/mteb/leaderboard

We introduce Instructor👨‍🏫, an instruction-finetuned text embedding model that can generate text embeddings tailored to any task (e.g., classification, retrieval, clustering, text evaluation, etc.) and domains (e.g., science, finance, etc.) by simply providing the task instruction, without any finetuning. Instructor👨‍ achieves sota on 70 diverse embedding tasks! The model is easy to use with our customized sentence-transformer library. For more details, check out our paper and project page!

Types of changes

• New feature (non-breaking change which adds functionality)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING page.
• I have added tests to cover my changes.
• All new and existing tests passed.