style: remove backticks

Signed-off-by: Athan <[email protected]>

Author: kgryte

lib/node_modules/@stdlib/stats/incr/nanstdev/README.md

@@ -53,7 +53,7 @@ var incrnanstdev = require( '@stdlib/stats/incr/nanstdev' );
 
 #### incrnanstdev( \[mean] )
 
-Returns an accumulator `function` which incrementally computes a [corrected sample standard deviation][sample-stdev], ignoring `NaN` values.
+Returns an accumulator function which incrementally computes a [corrected sample standard deviation][sample-stdev], ignoring `NaN` values.
 
 ```javascript
 var accumulator = incrnanstdev();