Environments:

• Prettier Version: 2.1.2
• Running Prettier via: CLI
• Runtime: Node.js 14.15.0
• Operating System: macOS
• Prettier plugins (if any):

Steps to reproduce:

$ prettier --write .eslintrc    
.eslintrc 32ms
$ prettier --write .stylelintrc 
[error] No parser could be inferred for file: .stylelintrc

Prettier treats .eslintrc (without extension) as JSON, but doesn't do the same to .stylelintrc or other cosmiconfig style config files.

Expected behavior

• Option 1: Add some more popular *rc as built-in supported.
• Option 2: Add a new cosmiconfig parser and use it as default for any *rc files without an extension.