Add alert message component and documentation

- Add custom alert component to simplify the use of custom alerts
- Add documentation for using the custom alert
- Update the login error alert to use the alert component instead of
the Bootstrap-vue component.
- Register alert component in enhanceApp
- Replace Sass variables used in the StatusIcon component style block
to use the Boostrap theme-color and gray Sass functions so the colors
can be used in the Vuepress documentation custom components

Signed-off-by: Derick Montague <derick.montague@ibm.com>
Change-Id: Ibd93402c919a42bd5c24cc9e7c6c8fc6f17a4db4
diff --git a/docs/.vuepress/enhanceApp.js b/docs/.vuepress/enhanceApp.js
index 799cf20..72fd24d 100644
--- a/docs/.vuepress/enhanceApp.js
+++ b/docs/.vuepress/enhanceApp.js
@@ -1,19 +1,22 @@
 
-// OpenBMC Imports
 import "../../src/assets/styles/_obmc-custom.scss";
+import Alert from "../../src/components/Global/Alert";
 import BVToastMixin from "../../src/components/Mixins/BVToastMixin";
 
 // Bootstrap-vue Plugin imports
 import {
+    AlertPlugin,
     ButtonPlugin,
     ToastPlugin
   } from 'bootstrap-vue';
 
 
 export default ({ Vue }) => {
+      Vue.use(AlertPlugin);
       Vue.use(ButtonPlugin);
       Vue.use(ToastPlugin);
 
       // BMC Components and Mixins
+      Vue.component('Alert', Alert);
       Vue.mixin('BVToastMixin', BVToastMixin);
 }
\ No newline at end of file