v4.0.0

• Support ESLint 9+ by switching to a flat config format.
• Revise the rule list to remove old deprecated rules and add a few new ones.
• Drop Node-related rules (preferring to use the Node plugin on a per-project basis).
• Keep stylistic rules by using @stylistic/js plugin.

v3.0.0

ES-targeted overhaul, since I switched to ES6 / modules (+ rollup and buble) for my projects.