Use single quote instead of backtick

doc/tutorials/background.md

@@ -37,13 +37,13 @@ Class hierarchies grouped by their parent are provided in a subfolder of the pac
 For convenience, these are also available as named exports, e.g.
 
 ```js
-import {Map, View} from `ol`;
-import {Tile, Vector} from `ol/layer`;
+import {Map, View} from 'ol';
+import {Tile, Vector} from 'ol/layer';
 ```
 
 In addition to these re-exported classes, modules with lowercase names also provide constants or functions as named exports:
 
 ```js
-import {inherits} from `ol`;
-import {fromLonLat} from `ol/proj`;
+import {inherits} from 'ol';
+import {fromLonLat} from 'ol/proj';
 ```