fix: readme fix;

README.md

@@ -71,7 +71,7 @@ This function caches the value to avoid increased resources usage. In case you w
 
 #### One more clarification
 This function has inner cache due to scrollbars width is not intended to be changed since initial call, but it can in case you toggle the device emulation.  
-If you need function to recalculate the width, set `scrollbarWidth.__cache` to `undefined` and next call will perform return the fresh value.
+If you need function to recalculate the width call it with `true` parameter and get new value or set `scrollbarWidth.__cache` to `undefined` and next call will return the fresh value.
 
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