Add bottom black gradient to iso boot background

src/boot-menu/syslinux.svg

@@ -24,13 +24,13 @@
      inkscape:pageopacity="0"
      inkscape:pagecheckerboard="1"
      showgrid="false"
-     inkscape:zoom="1.61875"
+     inkscape:zoom="0.5"
-     inkscape:cx="461.1583"
+     inkscape:cx="653"
-     inkscape:cy="118.91892"
+     inkscape:cy="-4"
-     inkscape:window-width="2406"
+     inkscape:window-width="2774"
-     inkscape:window-height="1655"
+     inkscape:window-height="1904"
-     inkscape:window-x="1080"
+     inkscape:window-x="1796"
-     inkscape:window-y="123"
+     inkscape:window-y="189"
      inkscape:window-maximized="0"
      inkscape:current-layer="svg43"
      borderlayer="true"
@@ -39,6 +39,18 @@
      inkscape:deskcolor="#d1d1d1" />
   <defs
      id="defs22">
+    <linearGradient
+       id="linearGradient1"
+       inkscape:collect="always">
+      <stop
+         style="stop-color:#000000;stop-opacity:0.40000001;"
+         offset="0"
+         id="stop1" />
+      <stop
+         style="stop-color:#007ebd;stop-opacity:0;"
+         offset="1"
+         id="stop2" />
+    </linearGradient>
     <filter
        id="c"
        x="-0.01569312"
@@ -475,6 +487,16 @@
          stdDeviation="12.664849"
          id="feGaussianBlur1" />
     </filter>
+    <linearGradient
+       inkscape:collect="always"
+       xlink:href="#linearGradient1"
+       id="linearGradient2"
+       x1="134.48549"
+       y1="196.33054"
+       x2="134.48549"
+       y2="157.93575"
+       gradientUnits="userSpaceOnUse"
+       gradientTransform="matrix(1,0,0,1.289761,0,-76.744011)" />
   </defs>
   <g
      id="b"
@@ -498,6 +520,13 @@
        transform="matrix(-1.0052332,0,0,-1.0052332,55.856994,-0.15326897)"
        style="filter:url(#filter6)" />
   </g>
+  <rect
+     style="opacity:1;mix-blend-mode:multiply;fill:url(#linearGradient2);fill-opacity:1;stroke-width:4.50722;stroke-linecap:round;stroke-linejoin:round;stroke-miterlimit:16.8;paint-order:stroke fill markers"
+     id="rect1"
+     width="395.0925"
+     height="166.54016"
+     x="-62.082249"
+     y="98.31266" />
   <use
      transform="translate(1.2106245e-5)"
      width="100%"