Added citation styling (#196)

Added styling for the citation block. Closes #173

Author: SociableSteve

assets/style/pages/packages.css

@@ -115,6 +115,13 @@ ul.ui-autocomplete li::before {
   content: none;
 }
 
+.bioc-citation {
+  background-color: var(--neutral-n50);
+  border: 1px solid var(--neutral-n75);
+  padding: 1rem 1rem 0;
+  margin: 0.5rem 0 1rem;
+}
+
 @media (max-device-width: 1250px), (max-width: 1250px) {
   .biocViewsTreeContainer {
     display: flex;