fix(dropdown): small enhancements (#1793)

* Use `.nav-link` instead of `.btn` in a navbar.
* Remove the cut border on split-dropdown when shown.
* Remove border on `.nav-link` since we declare border on each nav.

scss/_button-group.scss

@@ -87,7 +87,7 @@
   // Boosted mod
   .btn-group:not(.dropstart) &,
   .dropstart & ~ .btn {
-    &:not(:hover):not(:focus):not(:active) {
+    &:not(:hover):not(:focus):not(:active):not(.show) {
       border-left-color: transparent;
 
       &::before {

scss/_nav.scss

@@ -22,14 +22,15 @@
 }
 
 .nav-link {
-  display: flex; // Boosted mod
+  display: flex; // Boosted mod: instead of `block`
   align-items: center; // Boosted mod
   padding: var(--#{$prefix}nav-link-padding-y) var(--#{$prefix}nav-link-padding-x);
   @include font-size(var(--#{$prefix}nav-link-font-size));
   font-weight: var(--#{$prefix}nav-link-font-weight);
   color: var(--#{$prefix}nav-link-color);
   text-decoration: if($link-decoration == none, null, none);
-  background: none; // Boosted mod: Prevent dropdown's background to interfere
+  background: none;
+  border: 0;
   @include transition($nav-link-transition);
 
   // Boosted mod: no focus

site/content/docs/5.2/components/dropdowns.md

@@ -248,7 +248,7 @@ And putting it to use in a navbar:
     <div class="collapse navbar-collapse" id="navbarNavDarkDropdown">
       <ul class="navbar-nav">
         <li class="nav-item dropdown">
-          <button class="btn btn-dark dropdown-toggle" data-bs-toggle="dropdown" aria-expanded="false">
+          <button class="nav-link dropdown-toggle" data-bs-toggle="dropdown" aria-expanded="false">
             Dropdown
           </button>
           <ul class="dropdown-menu dropdown-menu-dark">