docs: use correct buffer during output ndarray construction

[MeKaustubh07]

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Description

These modules had incorrect buffer assignments (xbuf used instead of ybuf) in their lib/index.js and lib/main.js implementations.

This pull request:

• fix: resolve incorrect buffer assignment in ndarray cumulative sum

Related Issues

blas/ext/base/ndarray/scusum
blas/ext/base/ndarray/gcusum
blas/ext/base/ndarray/dcusum

This pull request has the following related issues:

• #{{TODO: add related issue number}}

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Coverage Report

Package	Statements	Branches	Functions	Lines
blas/ext/base/ndarray/dcusum	$\color{green}131/131$ $\color{green}+100.00%$	$\color{green}3/3$ $\color{green}+100.00%$	$\color{green}1/1$ $\color{green}+100.00%$	$\color{green}131/131$ $\color{green}+100.00%$
blas/ext/base/ndarray/gcusum	$\color{green}129/129$ $\color{green}+100.00%$	$\color{green}3/3$ $\color{green}+100.00%$	$\color{green}1/1$ $\color{green}+100.00%$	$\color{green}129/129$ $\color{green}+100.00%$
blas/ext/base/ndarray/scusum	$\color{green}131/131$ $\color{green}+100.00%$	$\color{green}3/3$ $\color{green}+100.00%$	$\color{green}1/1$ $\color{green}+100.00%$	$\color{green}131/131$ $\color{green}+100.00%$

The above coverage report was generated for the changes in this PR.

[kgryte]

LGTM. Thanks for addressing, @MeKaustubh07!