fixed link to theming

Author: M-a-c

guides/mat-elevation.md

@@ -13,7 +13,7 @@ Elevation is implemented with a class, simply adding the class `mat-elevation-z#
 
 ## Mixins
 In order to use the mixin for Elevation you must 
-`@import '~@angular/material/core/style/_elevation.scss';`
+`@import '~@angular/material/theming';`
 $zValue must be a value between 0 and 24, inclusive.
 `@include mat-elevation($zValue);`
 

src/examples/elevation-overview/elevation-overview-example.scss

@@ -1,4 +1,4 @@
-@import '~@angular/material/core/style/_elevation.scss';
+@import '~@angular/material/theming';
 
 div {
     width: auto;