Max line length and Prettier/ESLint

[tvharris]

Prettier handles max line length loosely, whereas ESLint's max-len is a hard upper limit. If we want to handle the formatting with Prettier, while letting long lines (e.g., strings) trigger ESLint, we could use Prettier as a soft limit of 100 characters and ESLint as a hard limit of 120.

Prettier rule: "printWidth": 100
ESLint rule: "max-len": ["error", {"code": 120}]