Style the list and article paginators

* Remove the list item bullets
* Style the list items with "space between" so they will spread evenly

layouts/partials/paginator.html

@@ -1,4 +1,4 @@
-<nav>
+<nav class="paginator">
     <ul>
         <li>
             {{if .HasPrev}}

layouts/partials/prev-next-page.html

@@ -1,5 +1,5 @@
 {{ if not .Params.Menu }}
-<nav>
+<nav class="paginator">
     <ul>
         <li>
             {{ if .NextInSection }}

static/css/layout.css

@@ -19,4 +19,12 @@ nav.site-menu ul {
 
 nav.site-menu ul li {
   padding: 0.5em 0.5em 0.5em 0.5em;
-}
+}
+
+nav.paginator ul {
+  display: flex;
+  justify-content: space-between;
+  list-style-type: none;
+  padding-inline-start: 1em;
+  padding-inline-end: 1em;
+}