Minor nitpick on "Getting Started" docker compose documentation

[joba-1]

The docker compose example file has lines like /dev/ttyUSB0:/dev/ttyUSB0 or 8080:8080.
Since first and second value are equal it is hard to guess which is the host os and which is the docker value.
Easy enough, to find a hint elsewhere, but that was the only time I had to look around... :)
I'll add it if desired but I'm hesitant to just change docs of a project I have less than an hour experience with.