refactor: update sidebar color scheme and links

Author: mrholek

src/pug/_partials/sidebar.pug

@@ -1,4 +1,4 @@
-.sidebar.sidebar-fixed.border-end.sidebar-light#sidebar
+.sidebar.sidebar-fixed.border-end.sidebar-dark#sidebar
   .sidebar-header.border-bottom
     .sidebar-brand
       svg.sidebar-brand-full(width="88" height="32" alt="CoreUI Logo")
@@ -259,10 +259,9 @@
           use(xlink:href="node_modules/@coreui/icons/sprites/free.svg#cil-description")
         |  Docs
     li.nav-item
-      a.nav-link.nav-link-danger(href="https://coreui.io/product/bootstrap-dashboard-template/" target="_top")
-        svg.nav-icon
+      a.nav-link.text-primary.fw-semibold(href="https://coreui.io/product/bootstrap-dashboard-template/" target="_top")
+        svg.nav-icon.text-primary
           use(xlink:href="node_modules/@coreui/icons/sprites/free.svg#cil-layers")
-        |  Try CoreUI 
-        .fw-semibold.ms-1 PRO
+        |  Try CoreUI PRO
   .sidebar-footer.border-top.d-none.d-md-flex      
     button.sidebar-toggler(type="button" data-coreui-toggle="unfoldable")