change small things in README

README.md

 ![pipeline](https://codebase.helmholtz.cloud/hzb/epics/base/ubuntu_20_04/badges/docker_image_branch/pipeline.svg)
 # Epics base
+- Version of EPICS : `7.0.7`
+- Version of Ubuntu : `20.04`
+
 
 This image puts EPICS base at /opt/epics/base
 This image tries to keep the image relatively by deleting EPICS source and keeping the cache clean.