Add shutdown icon SVG and desktop entry for shutdown application

icons/shutdown.svg

@@ -0,0 +1,25 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<svg width="256" height="256" version="1.1"
+     xmlns="http://www.w3.org/2000/svg"
+     xmlns:xlink="http://www.w3.org/1999/xlink">
+  <defs>
+    <linearGradient id="Gradient" x1="0" x2="0" y1="0" y2="1">
+      <stop offset="0%" style="stop-color:#A51D2D;stop-opacity:1" />
+      <stop offset="100%" style="stop-color:#FF7800;stop-opacity:1" />
+    </linearGradient>
+    <filter id="alpha-to-white">
+      <feColorMatrix in="SourceGraphic" type="matrix"
+                     values="0 0 0 0 1 0 0 0 0 1 0 0 0 0 1 0 0 0 1 0"/>
+    </filter>
+    <g id="child-svg"><svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" fill="currentColor" height="16px" width="16px"><path d="M6.26489 3.80698L7.41191 5.44558C5.34875 6.89247 4 9.28873 4 12C4 16.4183 7.58172 20 12 20C16.4183 20 20 16.4183 20 12C20 9.28873 18.6512 6.89247 16.5881 5.44558L17.7351 3.80698C20.3141 5.61559 22 8.61091 22 12C22 17.5228 17.5228 22 12 22C6.47715 22 2 17.5228 2 12C2 8.61091 3.68594 5.61559 6.26489 3.80698ZM11 12V2H13V12H11Z" /></svg></g>
+  </defs>
+  <rect
+      width="256"
+      height="256"
+      fill="url(#Gradient)"
+      ry="128"
+      x="0"
+      y="0" />
+  <use xlink:href="#child-svg" filter="url(#alpha-to-white)"
+       transform="matrix(8,0,0,8,64,64)" />
+</svg>

src/shutdown.desktop

@@ -0,0 +1,5 @@
+[Desktop Entry]
+Type=Application
+Name=Shutdown
+Exec=/usr/bin/systemctl poweroff
+Icon=shutdown