CSS: Move icons to separate file

Signed-off-by: Julius Härtl <jus@bitgrid.net>

css/icons.scss

@@ -0,0 +1,42 @@
+/**
+ * Custom icons
+ */
+.icon-deck {
+  background-image: url('../img/deck-dark.svg');
+}
+
+.icon-group {
+  background-image: url('../../../settings/img/users.svg');
+}
+
+.icon-help {
+  background-image: url('../../../settings/img/help.svg');
+}
+
+.icon-add-white {
+  background-image: url('../img/add-white.svg');
+}
+
+.icon-archive {
+  background-image: url('../img/archive.svg');
+}
+
+.icon-archive-white {
+  background-image: url('../img/archive-white.svg');
+}
+
+.icon-details {
+  background-image: url('../img/details.svg');
+}
+
+.icon-details-white {
+  background-image: url('../img/details-white.svg');
+}
+
+.icon-home {
+  background-image: url('../../../core/img/places/home.svg');
+}
+
+.icon-badge {
+  background-image: url('../../../core/img/places/calendar-dark.svg');
+}