lint: make js code block standalone-parseable + fix test property order

- docs/rules/template-require-iframe-title.md: wrap the config example
  in `module.exports = {...}` so eslint can parse it as a standalone
  module (bare object literals are parsed as block statements, which
  trips 'missing semicolon' on the inner object).
- tests/lib/rules/template-require-iframe-title.js: move `output`
  before `options` on the allowWhitespaceOnlyTitle test case to match
  eslint-plugin/test-case-property-ordering's [code, output, options,
  errors] sequence.
- Prettier reflow of the config example (single-line rule array)
  applied via `prettier --write`.

Author: johanrd

docs/rules/template-require-iframe-title.md

@@ -9,7 +9,7 @@
 `<iframe>` elements must have a unique title property so assistive
 technology can convey their content to the user. The normative
 requirement is [WCAG SC 4.1.2 (Name, Role, Value)](https://www.w3.org/TR/UNDERSTANDING-WCAG20/ensure-compat-rsv.html);
-the `title` attribute is *one sufficient technique* for meeting it
+the `title` attribute is _one sufficient technique_ for meeting it
 (sufficient technique [H64](https://www.w3.org/WAI/WCAG21/Techniques/html/H64)).
 
 ## Examples
@@ -50,14 +50,11 @@ true` if your codebase needs it.
   still flagged.
 
 ```js
-{
+module.exports = {
   rules: {
-    'ember/template-require-iframe-title': [
-      'error',
-      { allowWhitespaceOnlyTitle: true },
-    ],
+    'ember/template-require-iframe-title': ['error', { allowWhitespaceOnlyTitle: true }],
   },
-}
+};
 ```
 
 ## References

tests/lib/rules/template-require-iframe-title.js

@@ -152,8 +152,8 @@ ruleTester.run('template-require-iframe-title', rule, {
     // (an empty string is not a whitespace string).
     {
       code: '<template><iframe title="" /></template>',
-      options: [{ allowWhitespaceOnlyTitle: true }],
       output: null,
+      options: [{ allowWhitespaceOnlyTitle: true }],
       errors: [{ messageId: 'emptyTitle' }],
     },
   ],