Configure Biome properly

[Boshen]

1. When running "./node_modules/.bin/biome format --write outline", it displays Formatted 1914 files in 275ms. Fixed 1811 files. What does "Fixed 1811 files." mean? How do I enforce formatter and nothing else?

2. biome.json configuration seems mandatory, can I disable it and just use the CLI?

3. biome refuses to format checker.ts because it's too long, I can't figure out how to make it format, tried all the size limit settings and nothing worked (?).

[ematipico]

I'll look into it. Can you please add me as an assignee too?