Enhance README with API reference and documentation

Added API reference and documentation link to README.

Author: vgvoleg

README.md

@@ -2,11 +2,18 @@
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 [![License](https://img.shields.io/badge/License-Apache%202.0-blue.svg)](https://github.com/ydb-platform/ydb-sqlalchemy/blob/main/LICENSE)
 [![PyPI version](https://badge.fury.io/py/ydb-sqlalchemy.svg)](https://badge.fury.io/py/ydb-sqlalchemy)
+[![API Reference](https://img.shields.io/badge/API-Reference-lightgreen.svg)](https://ydb-platform.github.io/ydb-sqlalchemy/api/index.html)
 [![Functional tests](https://github.com/ydb-platform/ydb-sqlalchemy/actions/workflows/tests.yml/badge.svg)](https://github.com/ydb-platform/ydb-sqlalchemy/actions/workflows/tests.yml)
 [![Style checks](https://github.com/ydb-platform/ydb-sqlalchemy/actions/workflows/style.yml/badge.svg)](https://github.com/ydb-platform/ydb-sqlalchemy/actions/workflows/style.yml)
 
 This repository contains YQL dialect for SqlAlchemy 2.0.
 
+---
+
+**Documentation**: <a href="https://ydb-platform.github.io/ydb-sqlalchemy" target="_blank">https://ydb-platform.github.io/ydb-sqlalchemy</a>
+
+---
+
 **Note**: Dialect also works with SqlAlchemy 1.4, but it is not fully tested.
 
 
@@ -168,4 +175,4 @@ It is possible to use YDB SA engine with `pandas` fuctions [to_sql()](https://pa
 
 * `to_sql` is not fully optimized to load huge datasets. It is recommended to use `method="multi"` and avoid setting a very large `chunksize`.
 
-* `read_sql` is not fully optimized to load huge datasets and could lead to significant memory consumptions.
+* `read_sql` is not fully optimized to load huge datasets and could lead to significant memory consumptions.