add config module and update exports in package.json

src/config/index.ts

@@ -0,0 +1,27 @@
+// SPDX-License-Identifier: MIT
+
+import { readFile } from "node:fs/promises";
+import os from "node:os";
+import path from "node:path";
+
+function getConfigDir(moduleName: string): string {
+  if (process.platform === "win32") {
+    return path.join(process.env.LOCALAPPDATA ?? path.join(os.homedir(), "AppData", "Local"), moduleName);
+  }
+
+  return path.join(process.env.XDG_CONFIG_HOME ?? path.join(os.homedir(), ".config"), moduleName);
+}
+
+export async function getConfig(moduleName: string): Promise<unknown> {
+  const configPath = path.join(getConfigDir(moduleName), "config.json");
+
+  return readFile(configPath, "utf8")
+    .then((configJson) => JSON.parse(configJson) as unknown)
+    .catch((err: unknown) => {
+      if ((err as { code?: string } | null)?.code === "ENOENT") {
+        return {};
+      }
+
+      throw err;
+    });
+}