Update documentation

Author: Konstantin Ivaschenko

README.md

@@ -3,7 +3,7 @@
 [![PyPI](https://img.shields.io/pypi/v/dxfeed)](https://pypi.org/project/dxfeed/)
 [![Documentation Status](https://readthedocs.org/projects/dxfeed/badge/?version=latest)](https://dxfeed.readthedocs.io/en/latest/?badge=latest)
 [![PyPI - Python Version](https://img.shields.io/pypi/pyversions/dxfeed)](https://pypi.org/project/dxfeed/)
-![Platform](https://img.shields.io/badge/platform-win--x64%20%7C%20linux--x64%20%7C%20osx--x64-lightgrey)
+[![Platform](https://img.shields.io/badge/platform-win--x64%20%7C%20linux--x64%20%7C%20osx--x64-lightgrey)
 [![PyPI - Wheel](https://img.shields.io/pypi/wheel/dxfeed)](https://pypi.org/project/dxfeed/)
 [![PyPI - License](https://img.shields.io/pypi/l/dxfeed)](https://github.com/dxFeed/dxfeed-python-api/blob/master/LICENSE)
 [![Test workflow](https://github.com/dxFeed/dxfeed-python-api/workflows/Test%20package/badge.svg)](https://github.com/dxFeed/dxfeed-python-api/actions)