Comments and Update for Elasticsearch

[supaeasy]

Added comments where I struggled.

The way it is configured everything works without having to tweak anything except for IMAP Settings. Just like the blog post says: one command to bring up everything: docker-compose up. Initially did not work at all for me Tested unter elementaryOS Hera, IMAP Account with STARTTLS

Great project, love that this is the first one I can contribute to!