docs: add transition notice (#16)

Signed-off-by: Panos Vagenas <pva@zurich.ibm.com>

Author: vagenas

README.md

@@ -1,54 +1,2 @@
-# Haystack Docling integration
-
-[![PyPI version](https://img.shields.io/pypi/v/docling-haystack)](https://pypi.org/project/docling-haystack/)
-[![PyPI - Python Version](https://img.shields.io/pypi/pyversions/docling-haystack)](https://pypi.org/project/docling-haystack/)
-[![Poetry](https://img.shields.io/endpoint?url=https://python-poetry.org/badge/v0.json)](https://python-poetry.org/)
-[![Code style: black](https://img.shields.io/badge/code%20style-black-000000.svg)](https://github.com/psf/black)
-[![Imports: isort](https://img.shields.io/badge/%20imports-isort-%231674b1?style=flat&labelColor=ef8336)](https://pycqa.github.io/isort/)
-[![Pydantic v2](https://img.shields.io/endpoint?url=https://raw.githubusercontent.com/pydantic/pydantic/main/docs/badge/v2.json)](https://pydantic.dev)
-[![pre-commit](https://img.shields.io/badge/pre--commit-enabled-brightgreen?logo=pre-commit&logoColor=white)](https://github.com/pre-commit/pre-commit)
-[![License MIT](https://img.shields.io/github/license/DS4SD/docling)](https://opensource.org/licenses/MIT)
-
-A [Docling](https://github.com/DS4SD/docling) integration for
-[Haystack](https://github.com/deepset-ai/haystack/).
-
-## Installation
-
-Simply install `docling-haystack` from your package manager, e.g. pip:
-```bash
-pip install docling-haystack
-```
-
-## Usage
-
-### Basic usage
-
-Basic usage of `DoclingConverter` looks as follows:
-
-```python
-from haystack import Pipeline
-from docling_haystack.converter import DoclingConverter
-
-idx_pipe = Pipeline()
-# ...
-converter = DoclingConverter()
-idx_pipe.add_component("converter", converter)
-# ...
-```
-### Advanced usage
-
-When initializing a `DoclingConverter`, you can use the following parameters:
-
-- `converter` (optional): any specific Docling `DocumentConverter` instance to use
-- `convert_kwargs` (optional): any specific kwargs for conversion execution
-- `export_type` (optional): export mode to use: `ExportType.DOC_CHUNKS` (default) or
-    `ExportType.MARKDOWN`
-- `md_export_kwargs` (optional): any specific Markdown export kwargs (for Markdown mode)
-- `chunker` (optional): any specific Docling chunker instance to use (for doc-chunk
-    mode)
-- `meta_extractor` (optional): any specific metadata extractor to use
-
-### Example
-
-For an end-to-end usage example, check out
-[this notebook](https://ds4sd.github.io/docling/examples/rag_haystack/).
+> [!IMPORTANT]
+> # 👉 This has moved to [Haystack Core Integrations](https://github.com/deepset-ai/haystack-core-integrations).