Add aliases for feedback classes

@JohannesHoppe

Author: fmalcher

README.md

@@ -6,7 +6,7 @@ Includes
 
 - Bootstrap CSS
 - Common form styles
-    - feedback classes `.feedback-red` and `.feedback-green`
+    - feedback classes `.feedback-error` and `.feedback-success` (and their aliases `.feedback-red` and `.feedback-green`)
     - Angular form styles for `.ng-valid` et al
 - Button styles
     - shortcut aliases for bootstrap buttons with right margin: `.btn-red`, `.btn-green`, `.btn-yellow`, `.btn-blue`, `.btn-grey`,

form-control.scss

@@ -9,13 +9,13 @@
 }
 
 .feedback {
-    &-red {
+    &-error, &-red {
         @extend .small;
         @extend .mt-1;
         @extend .text-danger;
     }
 
-    &-green {
+    &-success, &-green {
         @extend .small;
         @extend .mt-1;
         @extend .text-success;