add logo to README.md

Author: abelcarreras

README.md

@@ -3,10 +3,10 @@
 [![Test and Deploy](https://github.com/abelcarreras/posym/actions/workflows/python-publish.yml/badge.svg?branch=master)](https://github.com/abelcarreras/posym/actions/workflows/python-publish.yml)
 [![DOI](https://zenodo.org/badge/DOI/10.5281/zenodo.7261326.svg)](https://doi.org/10.5281/zenodo.7261326)
 
-<div style="display: flex; align-items: center; gap: 10px;">
-  <img src="posym_logo.png" alt="Logo" width="100">
-  <h1>PoSym</h1>
-</div>
+<h1>
+  <img src="posym_logo.png" alt="Logo" width="70" style="vertical-align: middle;">
+  PoSym
+</h1>
 
 A point symmetry analysis tool written in python designed for theoretical chemistry.
 This tool makes use of continuous symmetry measures (CSM) to provide a robust implementation