add alert to docs

assets/sass/_alert.scss

@@ -0,0 +1,67 @@
+.close {
+  float: right;
+  font-size: 20px;
+  font-weight: bold;
+  line-height: 18px;
+  color: #000000;
+  text-shadow: 0 1px 0 #ffffff;
+  opacity: 0.2;
+  filter: alpha(opacity=20);
+}
+.close:hover {
+  color: #000000;
+  text-decoration: none;
+  opacity: 0.4;
+  filter: alpha(opacity=40);
+  cursor: pointer;
+}
+
+.alert {
+  padding: 8px 35px 8px 14px;
+  margin-bottom: 18px;
+  text-shadow: 0 1px 0 rgba(255, 255, 255, 0.5);
+  background-color: #fcf8e3;
+  border: 1px solid #fbeed5;
+  -webkit-border-radius: 4px;
+  -moz-border-radius: 4px;
+  border-radius: 4px;
+  color: #c09853;
+  font-size: 15px;
+  line-height: 1.5;
+}
+.alert-heading {
+  color: inherit;
+}
+.alert .close {
+  position: relative;
+  top: -2px;
+  right: -21px;
+  line-height: 18px;
+}
+.alert-success {
+  background-color: #dff0d8;
+  border-color: #d6e9c6;
+  color: #468847;
+}
+.alert-danger,
+.alert-error {
+  background-color: #f2dede;
+  border-color: #eed3d7;
+  color: #b94a48;
+}
+.alert-info {
+  background-color: #d9edf7;
+  border-color: #bce8f1;
+  color: #3a87ad;
+}
+.alert-block {
+  padding-top: 14px;
+  padding-bottom: 14px;
+}
+.alert-block > p,
+.alert-block > ul {
+  margin-bottom: 0;
+}
+.alert-block p + p {
+  margin-top: 5px;
+}

assets/sass/app.scss

@@ -7,6 +7,7 @@
 'instantsearch',
 'instantsearch-theme-algolia',
 'izimodal',
+'alert',
 '../../node_modules/rancher-website-theme/assets/sass/theme';
 
 .modal-content {