Using color-scheme and light-dark() to implement dark mode (#154)

* Lint fixes.

* Implement light-dark().

* Lint css with biome, remove stylelint.

* Biome lint fixes.

* Dark mode adjustments.

* Style bug fixes.

* Colour adjustments.

* Move header and footer styles to base.

* Site header adjustments.

* Removing jQuery and umbrella libs. They where great but not needed anymore.

* Add colorScheme to optionally lock light/dark.

* Update README.

* Biome adjustments.

assets/css/components/_pager.css

@@ -5,7 +5,7 @@ is available. */
 
 .pagination,
 .pager {
-  --flex-inline-gap: .5rem;
+  --flex-inline-gap: 0.5rem;
 
   display: flex;
   flex-wrap: wrap;
@@ -31,9 +31,6 @@ is available. */
     padding-inline: 2px;
   }
 
-  .page-item {
-  }
-
   .active {
     font-weight: var(--fw-bold);
   }
@@ -42,13 +39,13 @@ is available. */
     .page-link {
       /* Re-set default cursor for disabled elements. */
       cursor: default;
-      color: var(--color-button-disabled);
+      color: var(--color-disabled);
 
       &:hover,
       &:focus,
       &:active {
         /* Override any link underlines and color changes. */
-        color: var(--color-button-disabled);
+        color: var(--color-disabled);
         text-decoration: none;
       }
     }