Update eslint to flat config

Fixes #425

Signed-off-by: David Thompson <davthomp@redhat.com>

Author: datho7561

.eslintrc.json

@@ -0,0 +1,17 @@
+// @ts-check
+
+import eslint from '@eslint/js';
+import tseslint from 'typescript-eslint';
+
+export default tseslint.config(
+  eslint.configs.recommended,
+  tseslint.configs.recommended,
+  {
+    files: [
+      "*/**test.ts"
+    ],
+    rules: {
+      "@typescript-eslint/no-unused-expressions": "off"
+    }
+  },
+);