Cleanup of icons.

src/styles/global/_base.scss

@@ -62,5 +62,5 @@ a {
 }
 
 .desktopnotify-icon {
-  background-image: url("../img/notify.png");
+  background-image: url("../img/logo-48x48.png");
 }

static/img/logo-square.svg

@@ -0,0 +1 @@
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 260 260"><defs><clipPath id="0"><path d="M 0,0 H 5244 V 1870.87 H 0 V 0"/></clipPath></defs><g transform="matrix(2.0166 0 0-2.0166 19.999 407.16)"><g transform="matrix(.1 0 0 .1-8.4 30.667)" clip-path="url(#0)"><path d="m667.43 1427.23c5.625 40.32 50 105 131.25 105 81.25 0 263.75 0 292.5 0 28.75 0 62.5-6.25 83.75 40-1.25-30-8.75-130-11.25-146.25-2.5-16.25-22.5-137.5-136.25-138.75-113.75 0-297.5 0-297.5 0 0 0-58.75 6.88-88.44-46.25-.191-.39 20.938 152.5 25.938 186.25" fill="#009534"/><path d="m135.79 939.4c11.23 81.49 99.82 212.27 262.03 212.27 162.22 0 526.57 0 583.97 0 57.4 0 124.78-12.637 167.2 80.86-2.49-60.65-17.47-262.81-22.46-295.66-4.99-32.851-44.92-277.97-272.01-280.5-227.1 0-593.95 0-593.95 0 0 0-118.99 13.1-176.56-93.5-.383-.801 41.801 308.3 51.781 376.53" fill="#84b819"/></g><text transform="scale(1-1)" y="-87.2" x="580" word-spacing="0" line-height="125%" letter-spacing="0" font-size="9.6" font-family="Bitstream Vera Sans"><tspan y="-87.2" x="580"/></text></g></svg>