docs: add JSDoc

lib/node_modules/@stdlib/fft/base/fftpack/float32/docs/types/index.d.ts

@@ -27,7 +27,26 @@ import decompose = require( '@stdlib/fft/base/fftpack/float32/decompose' );
 */
 interface Namespace {
 	/**
-	* TODO.
+	* Factorizes a sequence length into a product of integers and stores the results in a single-precision floating-point array.
+	*
+	* @param N - length of the sequence
+	* @param M - number of trial divisors
+	* @param initial - array of initial trial divisors
+	* @param si - stride length for `initial`
+	* @param oi - starting index for `initial`
+	* @param out - output array for storing factorization results
+	* @param so - stride length for `out`
+	* @param oo - starting index for `out`
+	* @returns number of factors into which `N` was decomposed
+	*
+	* @example
+	* var Float32Array = require( '@stdlib/array/float32' );
+	*
+	* var initial = new Float32Array( [ 3.0, 4.0, 2.0, 5.0 ] );
+	* var factors = new Float32Array( 4 );
+	*
+	* var numFactors = ns.decompose( 12, 4, initial, 1, 0, factors, 1, 0 );
+	* // returns 2
 	*/
 	decompose: typeof decompose;
 }