update the format of the web idl versions file (#194)

* update the format of the web idl versions file

* right-align

README.md

@@ -67,8 +67,8 @@ definitions:
   the number of breaking changes. This is currently WIP and some members may be
   added or removed.
 
-### Generation
+## Generation
 
-Most of the APIs in this package are generated from public assets.
-See the [tool directory](https://github.com/dart-lang/web/tree/main/tool) in the
-source repository to learn more.
+Most of the APIs in this package are generated from public assets. See the
+[tool directory](https://github.com/dart-lang/web/tree/main/tool) in the source
+repository to learn more.

tool/README.md

@@ -1,11 +1,13 @@
-## Web IDL version
+## Web IDL versions
 
 Based on:
 
 <!-- START updated by tool/update_bindings.dart. Do not modify by hand -->
-- @webref/css [6.11.0](https://www.npmjs.com/package/@webref/css/v/6.11.0)
-- @webref/elements [2.2.2](https://www.npmjs.com/package/@webref/elements/v/2.2.2)
-- @webref/idl [3.43.1](https://www.npmjs.com/package/@webref/idl/v/3.43.1)
+| Item | Version |
+| --- | --: |
+| `@webref/css` | [6.11.0](https://www.npmjs.com/package/@webref/css/v/6.11.0) |
+| `@webref/elements` | [2.2.2](https://www.npmjs.com/package/@webref/elements/v/2.2.2) |
+| `@webref/idl` | [3.43.1](https://www.npmjs.com/package/@webref/idl/v/3.43.1) |
 <!-- END updated by tool/update_bindings.dart. Do not modify by hand -->
 
 For instructions on re-generating the DOM bindings, see the

tool/update_bindings.dart

@@ -103,9 +103,11 @@ $_usage''');
   final idlVersion = _packageLockVersion(_webRefIdl);
   final versions = '''
 $_startComment
-- $_webRefCss [$cssVersion](https://www.npmjs.com/package/$_webRefCss/v/$cssVersion)
-- $_webRefElements [$elementsVersion](https://www.npmjs.com/package/$_webRefElements/v/$elementsVersion)
-- $_webRefIdl [$idlVersion](https://www.npmjs.com/package/$_webRefIdl/v/$idlVersion)
+| Item | Version |
+| --- | --: |
+| `$_webRefCss` | [$cssVersion](https://www.npmjs.com/package/$_webRefCss/v/$cssVersion) |
+| `$_webRefElements` | [$elementsVersion](https://www.npmjs.com/package/$_webRefElements/v/$elementsVersion) |
+| `$_webRefIdl` | [$idlVersion](https://www.npmjs.com/package/$_webRefIdl/v/$idlVersion) |
 ''';
 
   final newContent =