Move a number of files ahead of 2.1.1 launch.

This commit explicitly moves files around without modifying any content
so that Git can track them correctly.

Change-Id: I087d6d61d4e2d82ce06ad9ac0adf7327db94dd9c

model/composite/loop.xml

@@ -0,0 +1,33 @@
+<!-- Copyright 2021 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.
+-->
+
+<mujoco model="Loop">
+
+    <include file="scene.xml"/>
+
+    <option timestep="0.002" jacobian="dense"/>
+
+    <size nconmax="100" njmax="300" nstack="50000"/>
+
+    <worldbody>
+        <body name="B0" pos="0 0 1">
+            <freejoint/>
+            <composite type="loop" count="20 1 1" spacing="0.04" offset="0 0 2">
+                <joint kind="main" damping="0.005"/>
+                <geom type="capsule" size=".01 .015" rgba=".8 .2 .1 1"/>
+            </composite>
+        </body>
+    </worldbody>
+</mujoco>