Adding upstream version 5.2.3+dfsg.

Signed-off-by: Daniel Baumann <daniel@debian.org>

site/assets/scss/_clipboard-js.scss

@@ -0,0 +1,44 @@
+// clipboard.js
+//
+// JS-based `Copy` buttons for code snippets.
+
+.bd-clipboard,
+.bd-edit {
+  position: relative;
+  display: none;
+  float: right;
+
+  + .highlight {
+    margin-top: 0;
+  }
+
+  @include media-breakpoint-up(md) {
+    display: block;
+  }
+}
+
+.btn-clipboard,
+.btn-edit {
+  display: block;
+  padding: .5em;
+  line-height: 1;
+  color: $gray-900;
+  background-color: $gray-100;
+  border: 0;
+  @include border-radius(.25rem);
+
+  &:hover {
+    color: $primary;
+  }
+
+  &:focus {
+    z-index: 3;
+  }
+}
+
+.btn-clipboard {
+  position: relative;
+  z-index: 2;
+  margin-top: .75rem;
+  margin-right: .75rem;
+}