add service script, begin readme

.gitlab-ci.yml

@@ -43,7 +43,7 @@ release:
       RELEASE_FILE: opcua2mqtt-bridge-${CI_COMMIT_TAG}.tar.gz
     script:
         - pushd src
-        - tar -czvf ../$RELEASE_FILE --exclude=__pycache__ *
+        - tar -czvf ../$RELEASE_FILE --exclude=__pycache__ *.py *.json opcua2mqtt-bridge.service
         - popd
         - gitlabreleaseuploader.py -p "$PRIVATE_TOKEN" -i $CI_PROJECT_ID -u $CI_PROJECT_URL 
           -I https://devservice.krohne.com/git/