docs: Add logo to readme

Author: jvfe

README.md

@@ -3,6 +3,8 @@
 [![run with docker](https://img.shields.io/badge/run%20with-docker-0db7ed?labelColor=000000&logo=docker)](https://www.docker.com/)
 [![run with singularity](https://img.shields.io/badge/run%20with-singularity-1d355c.svg?labelColor=000000)](https://sylabs.io/docs/)
 
+![BulkRNA logo](assets/bulkrna_logo.png)
+
 ## Introduction
 
 **dalmolingroup/bulkrna** is an analysis pipeline for pre-processing, alignment and quantification of bulk RNA-Seq data.