Update README.md

README.md

@@ -8,4 +8,9 @@ docker build -t cta-archive .
 docker run cta-archive --name cta-archive -d -e API_KEY=<APIKey> -v <outputdir>/usr/cta-archive/output/
 ```
 
-By default, the script runs every 5 minutes to write json file to the <outputdir> above. This can be modified by updating the cronjob file.
+By default, the script runs every 5 minutes to write json file to the <outputdir> above. This can be modified by updating the following line in the Dockerfile:
+```
+RUN echo ' */5 * * * * /usr/local/bin/python3 /usr/cta-archive/archive.py ' >> /usr/cta-archive/cronjob
+
+# Where 5 indicates every 5th minute. 
+```