Honour prefers reduced motion for read receipts

res/css/_common.scss

@@ -28,6 +28,16 @@ $MessageTimestamp_width_hover: calc($MessageTimestamp_width - 2 * $EventTile_e2e
 
 :root {
     font-size: 10px;
+
+    --transition-short: .1s;
+    --transition-standard: .3s;
+}
+
+@media (prefers-reduced-motion) {
+    :root {
+        --transition-short: 0;
+        --transition-standard: 0;
+    }
 }
 
 html {

res/css/views/rooms/_EventTile.scss

@@ -284,8 +284,8 @@ $left-gutter: 64px;
     width: $font-14px;
 
     transition:
-        left .1s ease-out,
-        top .3s ease-out;
+        left var(--transition-short) ease-out,
+        top var(--transition-standard) ease-out;
 }
 
 .mx_EventTile_readAvatarRemainder {

src/Velociraptor.js

@@ -73,7 +73,7 @@ export default class Velociraptor extends React.Component {
                             }
                         });
 
-                    console.log("translation: "+oldNode.style.left+" -> "+c.props.style.left);
+                    // console.log("translation: "+oldNode.style.left+" -> "+c.props.style.left);
                 }
                 if (oldNode && oldNode.style.visibility === 'hidden' && c.props.style.visibility === 'visible') {
                     oldNode.style.visibility = c.props.style.visibility;