Fix mixins/extends confusion

sass/elements/other.sass

@@ -1,8 +1,8 @@
 .block
-  +block
+  @extend %block
 
 .delete
-  +delete
+  @extend %delete
 
 .heading
   display: block
@@ -12,7 +12,7 @@
   text-transform: uppercase
 
 .highlight
-  +block
+  @extend %block
   font-weight: $weight-normal
   max-width: 100%
   overflow: hidden
@@ -22,7 +22,7 @@
     max-width: 100%
 
 .loader
-  +loader
+  @extend %loader
 
 .number
   align-items: center