docs: improve doctests for complex number instances in math/base/special/cflipsignf#9011

Planeshifter merged 2 commits into

stdlib-js:developstdlib-js/stdlib:developfrom

aryan7071:docs-improve_math/base/special/cflipsignfaryan7071/stdlib:docs-improve_math/base/special/cflipsignfCopy head branch name to clipboard