Add JavaScript bindings and WASM support

Co-authored-by: Matija Kecman <matijak@google.com>
Co-authored-by: Sebastian Noreña Rendón <sebas.norena@creativa77.com.ar>
Co-authored-by: Kyle Bayes <kylebayes@google.com>
PiperOrigin-RevId: 826109484
Change-Id: I327fd54122762bd2e239cc31c602a3eb73051c26

wasm/demo_app/index.html

@@ -1,41 +0,0 @@
-<!--
- Copyright 2025 DeepMind Technologies Limited
-
- Licensed under the Apache License, Version 2.0 (the "License");
- you may not use this file except in compliance with the License.
- You may obtain a copy of the License at
-
-     http://www.apache.org/licenses/LICENSE-2.0
-
- Unless required by applicable law or agreed to in writing, software
- distributed under the License is distributed on an "AS IS" BASIS,
- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- See the License for the specific language governing permissions and
- limitations under the License.
--->
-
-<!DOCTYPE html>
-<html>
-  <head>
-    <meta charset="utf-8" />
-    <title>MuJoCo WebAssembly</title>
-    <style>
-      #button-container {
-        position: fixed;
-        bottom: 20px;
-        left: 50%;
-        transform: translateX(-50%);
-        display: flex;
-        gap: 10px;
-      }
-    </style>
-  </head>
-  <body>
-    <script type="module" src="./app.ts"></script>
-    <div id="button-container">
-      <button id="pause-button">Pause</button>
-      <button id="reset-button">Reset</button>
-      <button id="contact-button">Show Contacts</button>
-    </div>
-  </body>
-</html>