chore: SVG image fixed to make pre-commit happy

docs/_static/img/units.svg

@@ -1,7 +1,8 @@
 <?xml version="1.0" encoding="UTF-8" standalone="no"?>
 <svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" contentStyleType="text/css" height="456px" preserveAspectRatio="none" style="width:591px;height:456px;background:#FCFCFC;" version="1.1" viewBox="0 0 591 456" width="591px" zoomAndPan="magnify">
     <defs />
-    <g> <!--MD5=[197a77df23d290968e58c76a2239d979]
+    <g>
+        <!--MD5=[197a77df23d290968e58c76a2239d979]
 cluster Unit-->
         <g id="cluster_Unit">
             <a href="../../framework/units.html" target="_top" title="../../framework/units.html" xlink:actuate="onRequest" xlink:href="../../framework/units.html" xlink:show="new" xlink:title="../../framework/units.html" xlink:type="simple">
@@ -154,4 +155,4 @@ Language: en
 Country: US
 -->
     </g>
-</svg>
+</svg>