feat: update blas/ext TypeScript declarations

lib/node_modules/@stdlib/blas/ext/docs/types/index.d.ts

@@ -22,6 +22,7 @@
 
 import base = require( '@stdlib/blas/ext/base' );
 import circshift = require( '@stdlib/blas/ext/circshift' );
+import copyWithin = require( '@stdlib/blas/ext/copy-within' );
 import cusum = require( '@stdlib/blas/ext/cusum' );
 import findIndex = require( '@stdlib/blas/ext/find-index' );
 import findLastIndex = require( '@stdlib/blas/ext/find-last-index' );
@@ -76,6 +77,34 @@ interface Namespace {
 	*/
 	circshift: typeof circshift;
 
+	/**
+	* Performs an in-place copy of elements within an ndarray along an ndarray dimension.
+	*
+	* ## Notes
+	*
+	* -   The input ndarray is copied **in-place** (i.e., the input ndarray is **mutated**).
+	* -   When a `target`, `start`, and/or `end` index is negative, the respective index is determined relative to the last indexed element, with out-of-bounds indices clamped to index bounds.
+	*
+	* @param x - input ndarray
+	* @param target - target index
+	* @param start - source start index (inclusive)
+	* @param end - source end index (exclusive)
+	* @param options - function options
+	* @returns input ndarray
+	*
+	* @example
+	* var array = require( '@stdlib/ndarray/array' );
+	*
+	* var x = array( [ 1.0, 2.0, 3.0, 4.0, 5.0, 6.0 ] );
+	*
+	* var y = ns.copyWithin( x, 3, 1, 4 );
+	* // returns <ndarray>[ 1.0, 2.0, 3.0, 2.0, 3.0, 4.0 ]
+	*
+	* var bool = ( x === y );
+	* // returns true
+	*/
+	copyWithin: typeof copyWithin;
+
 	/**
 	* Computes the cumulative sum along one or more ndarray dimensions.
 	*