wip: add linters and formatters

eslint.config.js

@@ -0,0 +1,21 @@
+import eslint from "@eslint/js";
+import tseslint from "typescript-eslint";
+import astro from "eslint-plugin-astro";
+
+export default tseslint.config(
+  eslint.configs.recommended,
+  ...tseslint.configs.recommended,
+  ...astro.configs.recommended,
+  {
+    ignores: ["docs/**", ".astro/**"],
+  },
+  {
+    rules: {
+      // Allow unused vars prefixed with _
+      "@typescript-eslint/no-unused-vars": [
+        "error",
+        { argsIgnorePattern: "^_", varsIgnorePattern: "^_" },
+      ],
+    },
+  },
+);