docs: Fix inconsistencies in documentation

[shamblonaut]

This PR fixes some typos and formatting artifacts in the documentation files.

It also removes the version: field from the Docker Compose setup instruction, as it is obsolete.

Compose always uses the most recent schema to validate the Compose file, regardless of the version field.

Note: I also noticed the version field in the docker-compose.yml files, but was unsure whether removing it would affect backward compatibility.