Docs: warn against naming wgc router compose input file compose.yaml

[salsiy]

The local development uses compose.yaml as the input filename for wgc router compose:

https://cosmo-docs.wundergraph.com/tutorial/mastering-local-development-for-graphql-federation

compose.yaml is one of the reserved auto-discovery filenames for Docker Compose,When both files exist in the same directory, running docker-compose up picks up compose.yaml instead of docker-compose, causing the error

WARN Found multiple config files with supported names: compose.yaml, docker-compose.yml WARN Using compose.yaml validating compose.yaml: version must be a string

Suggestion
Update the tutorial to use a filename that doesn't conflict with Docker Compose