- Which options are exposed?
- The 15 most-configured ones: printWidth, tabWidth, useTabs, semi, singleQuote, trailingComma, bracketSpacing, arrowParens, endOfLine, plus language-specific overrides.
- CommonJS or module output?
- CommonJS by default (`module.exports = ...`) for broadest compatibility. Toggle to ESM for `export default ...`. Prettier supports both.
- Can I include per-filetype overrides?
- Yes — override section lets you set different rules for Markdown, YAML, JSON. Common pattern: different printWidth for prose vs code.
- JSON or JS format?
- JS lets you add comments and conditionals. JSON (.prettierrc) is simpler. Pick based on whether you need logic in the config.