refactor: restore valid docs links, and add new

src/views/buttons/BrandButtons.vue

@@ -5,6 +5,16 @@
         <CCard>
           <CCardHeader>
             <strong>Brand Button</strong>
+            <div class="c-card-header-actions">
+                <a 
+                  href="https://coreui.io/vue/docs/3.0/components/ButtonComponents" 
+                  class="card-header-action" 
+                  rel="noreferrer noopener" 
+                  target="_blank"
+                >
+                  <small class="text-muted">docs</small>
+                </a>
+              </div>
           </CCardHeader>
           <CCardBody>
             <small>Usage </small>

src/views/buttons/ButtonGroups.vue

@@ -7,11 +7,16 @@
             <CCardHeader>
               <i class="fa fa-align-justify"></i>
               <strong> Bootstrap button group</strong>
-              <!-- <div class="card-header-actions">
-                <a href="https://bootstrap-vue.js.org/docs/components/button-group" class="card-header-action" rel="noreferrer noopener" target="_blank">
+              <div class="c-card-header-actions">
+                <a 
+                  href="https://coreui.io/vue/docs/3.0/components/ButtonComponents" 
+                  class="card-header-action" 
+                  rel="noreferrer noopener" 
+                  target="_blank"
+                >
                   <small class="text-muted">docs</small>
                 </a>
-              </div> -->
+              </div>
             </CCardHeader>
             <CCardBody>
               <div>

src/views/buttons/Dropdowns.vue

@@ -7,11 +7,16 @@
             <CCardHeader>
               <i class="fa fa-align-justify"></i>
               <strong> Bootstrap Dropdown</strong>
-              <!-- <div class="card-header-actions">
-                <a href="https://bootstrap-vue.js.org/docs/components/dropdown" class="card-header-action" rel="noreferrer noopener" target="_blank">
+              <div class="c-card-header-actions">
+                <a 
+                  href="https://coreui.io/vue/docs/3.0/components/Dropdown" 
+                  class="card-header-action" 
+                  rel="noreferrer noopener" 
+                  target="_blank"
+                >
                   <small class="text-muted">docs</small>
                 </a>
-              </div> -->
+              </div>
             </CCardHeader>
             <CCardBody>
               <div>

src/views/buttons/StandardButtons.vue

@@ -3,6 +3,16 @@
     <CCard >
       <CCardHeader>
         <strong>Standard buttons</strong>
+        <div class="c-card-header-actions">
+          <a 
+            href="https://coreui.io/vue/docs/3.0/components/ButtonComponents" 
+            class="card-header-action" 
+            rel="noreferrer noopener" 
+            target="_blank"
+          >
+            <small class="text-muted">docs</small>
+          </a>
+        </div>
       </CCardHeader>
       <CCardBody>
         <CRow class="c-align-items-center">