Install.md

@@ -6,6 +6,12 @@ Stork has only very rudimentary end user installation instructions. *Very* early
 
 ## Ubuntu (docker)
 
+On Ubuntu 20, you need to install couple packages first:
+
+```
+$ sudo apt install rake docker docker-compose python3-sphinx-rtd-theme openjdk-11-jre-headless
+```
+
 Get the stork sources, then:
 ```
 $ rake docker_up