Add initial navbar

This includes all boards, as well as report counts if the user is an
admin.

Signed-off-by: Alek Ratzloff <alekratz@gmail.com>

board/static/board/restricted.css

@@ -0,0 +1,8 @@
+/* Nav */
+.nav_admin {
+    float: right;
+}
+
+.nav_report_urgent {
+    color: var(--error);
+}

board/static/board/style.css

@@ -6,6 +6,7 @@
     --activated: #888;
     --post-background: #d9d9d9;
     --reply-background: #eee;
+    --error: #f00;
 }
 
 body {
@@ -169,6 +170,11 @@ th {
     font-size: smaller;
 }
 
+/* Nav */
+nav {
+    font-size: small;
+}
+
 /* Misc */
 
 a:link {