Added footsteps, new tree, various other tweaks

addons/proton_scatter/icons/arrow_down.svg

@@ -0,0 +1,44 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<svg
+   clip-rule="evenodd"
+   fill-rule="evenodd"
+   stroke-linecap="round"
+   stroke-linejoin="round"
+   viewBox="0 0 12 12"
+   version="1.1"
+   id="svg4"
+   sodipodi:docname="arrow_down.svg"
+   inkscape:version="1.1.2 (0a00cf5339, 2022-02-04, custom)"
+   xmlns:inkscape="http://www.inkscape.org/namespaces/inkscape"
+   xmlns:sodipodi="http://sodipodi.sourceforge.net/DTD/sodipodi-0.dtd"
+   xmlns="http://www.w3.org/2000/svg"
+   xmlns:svg="http://www.w3.org/2000/svg">
+  <defs
+     id="defs8" />
+  <sodipodi:namedview
+     id="namedview6"
+     pagecolor="#ffffff"
+     bordercolor="#666666"
+     borderopacity="1.0"
+     inkscape:pageshadow="2"
+     inkscape:pageopacity="0.0"
+     inkscape:pagecheckerboard="0"
+     showgrid="false"
+     inkscape:zoom="52.5"
+     inkscape:cx="5.9904762"
+     inkscape:cy="6.0095238"
+     inkscape:window-width="2530"
+     inkscape:window-height="1050"
+     inkscape:window-x="30"
+     inkscape:window-y="0"
+     inkscape:window-maximized="1"
+     inkscape:current-layer="svg4" />
+  <path
+     d="m3 5 3 3 3-3"
+     fill="none"
+     stroke="#fff"
+     stroke-opacity=".39"
+     stroke-width="2"
+     id="path2"
+     style="stroke:#ffffff;stroke-opacity:1" />
+</svg>