Research what ram is needed for ES - tune compose - update docs

[milutz]

ES ram size is currently set to 4G, this causes problems if you want to tryout conveyor on a smaller VM and/or default memory allocations on Mac/Windows docker.

We need to research how much ES ram is required to import some typical sized file - say 50m then:

1. set compose to that level
2. add docs explaining thats what the compose is tuned for, and explain how to tune it up for higher levels