feat: indexOf docs

Author: adityacodes30

lib/node_modules/@stdlib/array/fixed-endian-factory/README.md

@@ -338,6 +338,27 @@ v = arr.at( -100 );
 // returns undefined
 ```
 
+<a name="method-index-of"></a>
+
+#### TypedArrayFE.prototype.indexOf( searchElement\[, fromIndex] )
+
+Returns the first index at which a given element can be found in the typed array, or `-1` if it is not present.
+
+```javascript
+var Float64ArrayFE = fixedEndianFactory( 'float64' );
+
+var arr = new Float64ArrayFE( 'little-endian', [ 1.0, 2.0, 3.0, 4.0 ] );
+
+var idx = arr.indexOf( 2.0 );
+// returns 1
+
+idx = arr.indexOf( 5.0 );
+// returns -1
+
+idx = arr.indexOf( 3.0, 3 );
+// returns -1
+```
+
 <a name="method-every"></a>
 
 #### TypedArrayFE.prototype.every( predicate\[, thisArg] )