docs: add example example with code from README/documentation (#130)

examples/simple-hard-coded.js

@@ -0,0 +1,26 @@
+'use strict';
+
+// This example is used in the documentation.
+
+// 1. const { parseArgs } = require('node:util'); // from node
+// 2. const { parseArgs } = require('@pkgjs/parseargs'); // from package
+const { parseArgs } = require('..'); // in repo
+
+const args = ['-f', '--bar', 'b'];
+const options = {
+  foo: {
+    type: 'boolean',
+    short: 'f'
+  },
+  bar: {
+    type: 'string'
+  }
+};
+const {
+  values,
+  positionals
+} = parseArgs({ args, options });
+console.log(values, positionals);
+
+// Try the following:
+//    node simple-hard-coded.js