docs: update description based on conventions

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

Author: kgryte

lib/node_modules/@stdlib/ndarray/flatten/lib/main.js

@@ -48,8 +48,7 @@ var format = require( '@stdlib/string/format' );
 * @param {string} [options.order='row-major'] - order in which input ndarray elements are flattened
 * @throws {TypeError} first argument must be an ndarray-like object
 * @throws {TypeError} options argument must be an object
-* @throws {TypeError} options.depth must be a nonnegative integer
-* @throws {TypeError} options.order must be a recognized order
+* @throws {TypeError} must provide valid options
 * @returns {ndarray} output ndarray
 *
 * @example